In the Khasi Hills of northeastern India, building a bridge can take much of a person’s lifetime. Villagers guide the roots of a tree across a stream, secure them on the opposite bank and return for years to direct fresh growth. Eventually the roots form a crossing strong enough for people to walk on. Those who use the bridge must keep caring for it, often continuing work begun by their parents or grandparents. In Meghalaya, these living crossings provide a practical route through terrain where rivers become difficult to pass during the monsoon.
The Khasi and Jaintia communities call these bridges jingkieng jri. Most use the aerial roots of Ficus elastica, the India rubber tree, growing in the steep river valleys below Meghalaya’s Shillong Plateau. They connect settlements with fields and markets, or link paths across streams that would otherwise cut people off. The structure stays connected to a living plant. Even after the walkway can carry people, roots continue to grow, thicken and branch, and local builders keep training them into place.
Some of the older crossings have woven walkways, living handrails and supporting roots so closely integrated with the banks that the whole structure seems to belong to the surrounding forest. Every part of that arrangement requires people to direct the roots as they grow. Builders decide where the tree should grow, which roots to extend across the river, how to anchor them and when a section needs reinforcement. A mature living root bridge represents many years of observation, skilled work and shared responsibility.
A crossing built for Meghalaya's rivers
Meghalaya occupies the southern edge of the Shillong Plateau. Here, short rivers descend steeply towards the lowlands of Bangladesh, and monsoon rain can transform an ordinary watercourse into a serious obstacle. Bridges made from bamboo or timber can be built quickly, but flooding, rot and unstable banks often mean rebuilding them. Concrete structures and roads can also provide crossings, although they may be expensive or difficult to construct in narrow forested valleys. Where suitable rubber fig trees grow and communities are able to maintain them, living roots offer a different solution.
The crossings belong to a network of paths serving different needs. A bridge may connect fields across a gorge, carry a route between villages or join a succession of steps, ladders and trails through a forest. India’s 2022 UNESCO tentative-list submission describes a wider tradition that also includes living platforms, ladders and structures used to limit erosion. They belong to the routes that local communities use to move through and work the land. What matters most to those caring for a bridge is often where it allows them to go.
The region’s heavy rainfall helps explain the need for dependable crossings, but rain alone did not produce the tradition. People also needed to understand which sites could support rubber fig trees, how rivers behave and how roots respond to years of careful training. The work demands patience because a bridge may become most useful long after its first builders began it. Living-root crossings can be found beyond Meghalaya, although the Khasi and Jaintia examples are unusually well recorded and remain active parts of the landscape.
Henry Yule described and illustrated a root bridge in his account of the Khasi Hills in 1844. His report establishes that the technique was in use long before modern scientists began documenting it. It cannot provide a reliable construction date for any particular bridge still standing. A crossing may contain roots of several ages, and because its supporting tree continues growing, the structure does not have one fixed set of materials that can easily be dated like those of a stone or timber bridge.
How a living root bridge is grown
A bridge begins with a usable site and an India rubber tree, whether one already growing beside the river or one planted for the purpose. Ficus elastica develops long aerial roots that usually grow down from its trunk and branches towards the soil. Builders select flexible young roots and direct them sideways over the gap. Bamboo, wooden frameworks and hollowed areca palm trunks may hold them in place while they extend. These guides support the construction process; the aim is for the living roots themselves eventually to carry the walkway.
Each guided root needs a firm destination. Villagers lay or tie it against the framework, aim it towards a tree on the far bank or encourage it to enter stable soil there. Once established on the other side, the root helps create a continuous connection across the stream. Further roots are led over, alongside and through the first, gradually forming side supports, handrails and a footway. Stones and soil may be added between them to make the surface easier to cross, but the structure underneath remains living wood that continues to change.
Ferdinand Ludwig, Wilfrid Middleton, Friederike Gallenmüller, Patrick Rogers and Thomas Speck documented this work in a 2019 field study. Their open-access study in Scientific Reports describes roots trained horizontally along a framework of dead wood before being planted into the opposite bank. As these roots thicken, they may produce further aerial roots for builders to redirect. The researchers also found considerable differences between bridges. Some rely heavily on a few large supporting roots, while others have tightly interwoven networks. The arrangement depends on the valley and on the builders who worked there.
There is no fixed moment when every root bridge becomes safe to walk on. The United Nations Development Programme reports an approximate growing period of twenty to twenty-five years before a crossing may be usable. Actual readiness depends on the tree’s health, the dimensions and number of roots, how securely they are anchored, the length of the span, local weather and the work carried out on it. The estimated growing period means that builders must plan decades ahead. It does not mean that every structure reaching its twenty-fifth year has passed an engineering safety test.
During those years, villagers may still need a temporary bridge. In a 2025 documentary essay, Khasi scholar Randolph V. Langstieh describes the bamboo crossing over the Wah Jashar at Shiliang Jashar, where rebuilding has been documented annually since 1988. The bamboo bridge serves daily travel while providing a framework for roots being guided into a future permanent crossing. The two forms of construction operate together, because the community cannot simply stop crossing the river while it waits for a tree to grow.
Why the roots hold together
The India rubber tree belongs to the fig genus and has an unusual growth habit. It is sometimes called a facultative hemiepiphyte: it can begin life on another plant and later grow roots into the ground, although it may also establish itself independently. The aerial roots that emerge above ground are particularly useful for bridges. They remain relatively flexible while young and can later develop strong woody tissue. By directing roots horizontally instead of allowing them to descend vertically, builders influence the form those roots acquire as they mature.
The root’s vascular cambium, a layer of growing tissue, produces more material for support and for moving water and nutrients. This thickening is known as secondary growth. Researchers working on Meghalaya’s bridges found differences in root cross-sections and size associated with the direction in which they had been trained, even among roots of similar approximate ages. Their findings suggest a relationship between growth and mechanical conditions. They do not show that every footstep strengthens a bridge, or that living roots will repair all damage without intervention.
Another property helps turn separate roots into an interwoven support system. inosculation occurs when living plant tissues grow together after sustained contact. Builders guide roots against and around one another to encourage such unions. Where joining succeeds, the resulting network can function as more than several independent strands. But two roots touching or crossing have not necessarily formed a strong biological connection. The reliability of the whole bridge also depends on the wider arrangement of members and how securely the roots connect to trees and banks.
In their 2019 field survey, researchers combined measurements of roots and bridge spans with interviews about construction histories. They recorded spans from 2 to 52.7 metres at elevations ranging between 57 and 1,211 metres. That longest recorded span was exceptional: of the 73 spans they measured, 58 were shorter than 20 metres. The 52.7-metre crossing shows that builders can guide roots across considerable distances, while most recorded routes involved much shorter gaps.
The team inventoried 76 bridges, though later reports have given larger numbers for the region as a whole. The difference partly reflects how widely researchers surveyed and whether new, abandoned or unfinished structures were included. Neither the 76-bridge field sample nor a count of villages in heritage documents amounts to a definitive census. The researchers also described different ways the roots carry weight. Some networks hang between anchors; others have prominent arch-like or beam-like members. Comparisons with suspension bridges, trusses, arches and cable-supported structures help engineers describe the forces involved. They should not imply that villagers started with modern bridge plans. The shapes developed through repeated practical choices as roots grew.
Growth may strengthen the roots, but the trees and their anchor points remain vulnerable. Trees develop diseases, floods can tear away supports, erosion can loosen an anchor, and a bridge left without maintenance may cease to be usable. In the 2019 study, residents described losses from fire, flooding and landslides. The researchers also saw a difference between groups of bridges near settlements that were regularly maintained and isolated examples that had been neglected. A living structure has capacities unavailable to cut timber, but those capacities depend on the condition of the tree and continued care by people.
Maintenance is part of construction
Even after a bridge carries regular traffic, work on it continues. New roots may be directed towards weaker parts, side supports added, temporary guides repaired and the walkway adjusted. A century-old bridge can therefore contain recently trained roots alongside material shaped several generations earlier. The age of the crossing tells us little about the exact age of every component, and its visible appearance seldom reveals a precise year when construction was completed.
Builders have to judge whether a young root can be redirected safely, whether its anchorage on the far bank will hold, and how future growth may change the crossing. Stones placed among the roots may make walking easier, but too much weight or poorly positioned material could interfere with drainage and growth. The soil beneath the trees deserves equal attention. However thick the central root network appears, erosion at the riverbank can threaten the entire crossing by undermining its living supports.
Local builders learn which rivers rise first during rain, which trees produce roots suitable for guiding, where handrails are essential and how often scaffolds must be replaced. Such knowledge passes between generations through working on the bridges together. The Indian nomination documentation describes site selection, planting, nurturing and continuing maintenance as shared stages of the tradition. It is the people who know the crossing, rather than a set of fixed drawings, who often make decisions as it grows.
Bridge building takes place within local systems of landholding and communal work. Khasi communities are widely described as matrilineal, with descent and important inheritance rights passing through women. That does not establish one universal rule about who builds each bridge or who must maintain it. Customs, landholding and village arrangements vary, as does the availability of experienced builders. The UNESCO submission discusses the responsibilities of village dorbar institutions and the importance of collective care. Root bridges exist within these local relationships between land, households and community decision-making.
At Shiliang Jashar, Langstieh describes villagers rebuilding their bamboo crossing while roots are prepared for a future living span. His account also discusses work at Mawkyrnot. The two examples show how construction and maintenance pass between generations. The people who begin training a root may never be its principal users, and the people who inherit a usable bridge must also inherit the knowledge to maintain it. The crossing survives through both the continued growth of the tree and the work of those who come after its original builders.
The forest is part of the bridge
The bridge’s supporting tree is part of a wider forest. Rubber figs grow alongside streams and steep slopes, where the stability of soil and riverbanks matters for their roots. Their canopies and fruit also connect them to other organisms, while roots may help hold surrounding ground. None of this proves that each individual bridge prevents landslides or cools its stream by a measurable amount. Those effects would need to be tested at particular locations. Maintaining a crossing also requires attention to its living environment.
A 2025 genetics preprint by Tista Ghosh, Uma Ramakrishnan and Renee M. Borges investigated natural populations of Ficus elastica across Meghalaya. The researchers analysed genetic information from 308 trees and identified four regional clusters associated with the East Khasi, West Khasi, West Jaintia and Ri Bhoi hills. Their models indicated that the landscape’s topography and wind may affect connectivity, and that movement of genetic material among related trees was often limited to a few kilometres. This work concerns the broader tree populations on which future bridges may depend, rather than the carrying capacity of a particular crossing.
Protecting a bridge, then, involves more than caring for the roots already visible across a river. New roads, building and forest fragmentation may alter habitats, pollinator relationships and the dispersal of future trees. The authors of the genetics study argue that conservation should consider the landscape around these populations. Their results came from a 2025 preprint, which means they should be treated as reported findings that may not yet have passed independent journal peer review.
A separate 2020 assessment of regenerative design considered the bridges through environmental, social and governance measures. Its authors found advantages in local living materials and the continuation of community expertise, but also identified costs and difficulties. Reaching some bridges is hard for people with limited mobility. Tourism can bring waste, building pressure and heavier use of paths and crossings. Using living materials does not automatically prevent environmental or social problems.
The double-decker bridge and the pressures of tourism
Near Nongriat, two living root walkways cross at different heights, forming the well-known double-decker bridge. Images of this crossing have spread widely and brought international attention to Meghalaya’s builders. That unusual example is not representative of every root bridge. Many crossings are relatively modest structures used for daily travel, and their value to the communities looking after them lies in what they connect rather than how impressive they appear in photographs.
Visitors can support guides, homestays and other local businesses, and tourism income may help pay for continued maintenance. More visitors also put pressure on steep tracks and riverbanks. Crowded routes can erode, waste may become harder to manage and roots can be damaged by climbing, pulling or excessive use. What matters is how visitor access and fees are organised, who makes decisions and who benefits. Limits on access should reflect each bridge’s condition and the judgement of the people responsible for its care.
A 2026 tourism study by Adelbert Majaw and R. Chitra Sivasubramanian surveyed 152 people in Nongriat and Tyrna. Their analysis associated a sense of local distinctiveness with residents’ attitudes and behaviours towards supporting and protecting tourism. This provides evidence about those surveyed communities, though it cannot show that visitor growth benefits every root-bridge village in the same way. Managing tourism therefore requires attention to the communities whose maintenance and knowledge make the crossings possible.
The UNDP’s 2024 reporting describes conservation work involving local residents, including Morningstar Khongthaw. He emphasises the need for reliable crossings when heavy rain makes rivers hazardous to ford. The crossings were developed to keep people moving when the rivers were high. Continued tourism interest may help them receive attention, but they remain useful infrastructure that needs people to look after it.
What UNESCO recognition means, and what it does not
On 17 February 2022, India placed the Jingkieng Jri Living Root Bridge Cultural Landscapes on UNESCO’s World Heritage tentative list. This was an expression of the country’s intention to consider a formal nomination, not a decision to place the bridges on the World Heritage List. The submission described living bridges and related structures across more than seventy-five villages. It proposed that their engineering, collective traditions and relationship with the landscape gave them outstanding cultural importance.
The proposal concerns the continued practice of making and caring for living infrastructure, as well as the bridges themselves. Forests, streams and settlements form part of that setting, because the trees and the communities maintaining them cannot be separated from their surroundings. The Indian documentation makes arguments under cultural criteria concerning creative achievement, a living tradition and community beliefs. These are the grounds advanced for recognition. They do not mean UNESCO has already accepted every proposed criterion.
In January 2026, India submitted a nomination dossier for the 2026–27 World Heritage cycle. Reporting in October 2026 described an ICOMOS evaluation visit in Meghalaya. The nomination and evaluation represent further steps beyond tentative listing in 2022. They do not amount to confirmation that the living root bridges have been inscribed on the World Heritage List.
Heritage recognition may attract funding and help draw attention to the knowledge behind these structures. It can also bring additional tourists and the expectation that a bridge should always look like a familiar photograph. That expectation is difficult to reconcile with a living structure. Builders may need to weave in new roots, close a crossing temporarily if it becomes unsafe or change its course as a riverbank shifts. Conserving the tradition requires allowing this work to continue, rather than treating each bridge as a monument that must retain one unchanging form.
What engineers can learn from roots
For engineers, the Meghalaya bridges raise questions about what it means to construct and maintain a structure. Conventional bridges are assembled from materials that generally deteriorate through exposure and use, even when good design extends their service lives. A root bridge can begin with comparatively slender living members and develop further supports as roots grow and people guide them. Growth during use is one reason engineers study the technique. It does not make living bridges indefinitely strong or free from maintenance.
Ferdinand Ludwig and colleagues use the term Baubotanik for architectural approaches that incorporate living trees. Their work has drawn on Meghalaya’s Khasi and Jaintia bridges while developing ways to document structures that change with growth. Researchers at the Technical University of Munich, for example, have used photogrammetric point clouds to map living joints and reconstruct their branching geometry. A detailed three-dimensional model records the condition of a structure when it was surveyed. Engineers also need to account for how living components may change over subsequent decades.
Before applying such ideas elsewhere, engineers need to establish how the materials behave. The load a root can carry depends on its thickness and condition; its stiffness may vary with moisture and age. Roots that look joined may have formed continuous living tissue or may simply be in contact. A 2019 experimental investigation by F. A. Hassan and C. J. Burgoyne tested aerial roots under tension and modelled a bridge using photogrammetry. The experiments offer measurements and useful methods, although findings from selected samples cannot establish that every existing crossing is safe.
The technique also depends on a setting suitable for rubber fig trees, a stable place to anchor them and years in which to train their roots. Scaffolding may remain necessary for a long time, followed by ongoing inspection and stewardship. Conditions in many cities are unsuitable, while heavy vehicles and very different climates pose demands that Meghalaya’s footbridges were never built to meet. Their construction principles can inform modern engineering without making them a ready substitute for concrete or steel bridges everywhere.
A living root bridge carries the work of several generations at once. Older roots record decisions made by builders who may be gone, while young growth is still being shaped by people who use the crossing today. The strength of such a bridge comes from the tree, the terrain and years of attentive human work. To keep it functioning, that work has to continue.
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