Archaeologists working in the forest across the river from Machu Picchu have mapped more than 2.5 kilometres of roads that no modern visitor knew existed. The routes were built by hand centuries ago and then swallowed by dense cloud forest, invisible from the ground and from the air until a laser-based survey cut through the canopy to reveal them. The find adds an entirely new stretch of infrastructure to one of the most studied archaeological landscapes on Earth.
Two weeks of scanning across the valley
The survey was carried out by a Polish-Peruvian team over roughly two weeks in late July and early August 2026, using LiDAR, a remote-sensing method that fires rapid laser pulses from a drone or aircraft flying over the terrain and measures how long each pulse takes to bounce back. Because some of those pulses slip through gaps in the vegetation and strike the ground itself, the technique can generate a detailed map of the forest floor even where dense tropical canopy makes the terrain impossible to see, or walk, directly. The work was funded by the University of Warsaw and coordinated with Peru’s Machu Picchu National Archaeological Park.
A road running to the Mandor Wall
The newly mapped routes sit on the opposite side of the Urubamba Valley from Machu Picchu itself, in an area associated with a structure known as the Mandor Wall. The main road identified in the survey runs for at least 1.2 kilometres of the total 2.5 kilometres mapped, and leads toward a set of platforms and terraces that had not been formally documented before this fieldwork, according to a release from the University of Warsaw. Because the site sits directly across the river from the citadel, on ground rarely explored despite its proximity to one of the most visited archaeological sites in South America, the discovery underscores how much of the surrounding landscape has gone unmapped simply because the vegetation made it impractical to survey on foot.
Engineering built for a steep, forested valley
The road’s layout follows a zigzag pattern as it climbs and descends the valley’s steep terrain, a design consistent with known Inca road-building practice in mountainous country. Researchers point to construction features along the route, including retaining elements and surface preparation, that are compatible with Inca engineering standards seen elsewhere in the empire’s road network, which at its height connected settlements across thousands of kilometres of the Andes. The presence of that engineering on a route this close to Machu Picchu, yet never previously recorded, suggests the citadel’s immediate surroundings were more heavily developed than the visible ruins alone indicate.
The wider Inca road system, sometimes referred to by its Quechua name Qhapaq Ñan, once linked settlements from present-day Ecuador and Colombia down through Peru, Bolivia, Chile and Argentina, forming one of the largest engineered transportation networks in the pre-industrial world. Individual sections of that network have been recognized internationally for their engineering, and a newly confirmed segment this close to Machu Picchu adds a fresh data point to how the system was extended into the steepest, most heavily forested terrain the empire controlled.
What the platforms and terraces were built for
Alongside the road, the LiDAR data revealed a series of platforms and terraces whose original function is not yet confirmed. Researchers consider agricultural use plausible, since terracing for planting is common throughout the Machu Picchu area, but a ceremonial or administrative purpose has not been ruled out either, particularly given the road’s apparent destination at a distinct architectural feature rather than open farmland. Determining which explanation fits will likely require ground survey and possibly excavation at the platforms themselves, work that has not yet been carried out.
Part of a wider network of more than 60 sites
Machu Picchu National Archaeological Park already contains more than 60 recorded archaeological sites connected by a broader road network, and the newly identified route adds to that existing system rather than standing apart from it. Fieldwork supervision for the project was led by Nino del Solar Velarde, who coordinates archaeological research for the park, working alongside the University of Warsaw’s Centre for Andean Studies. Framing the Mandor Wall route as an extension of a documented network, rather than an isolated find, is part of why researchers consider it significant: it suggests the settlement pattern around Machu Picchu was more interconnected than the surviving above-ground evidence had shown.
Why more of the valley may still be unmapped
Because this discovery came from a relatively short, targeted survey rather than a comprehensive scan of the entire park, researchers do not consider the current find complete. Large sections of the forest on both sides of the Urubamba Valley remain unsurveyed by LiDAR, and given how much new material turned up in just two weeks of fieldwork, further stretches of the same road, or entirely separate routes, are considered likely to exist under the canopy elsewhere in the park. Extending the survey would require additional funding and flight time, but the results from this round of fieldwork make a strong case for prioritizing it.
Part of the reason so much has stayed hidden for so long is practical rather than scientific: the terrain across the river from Machu Picchu is steep, unstable underfoot and covered in vegetation thick enough to hide a stone road just a few metres away from a walking path. Ground survey teams can spend days covering territory that a single LiDAR flight documents in hours, which is why remote sensing has become the standard first step before archaeologists commit to the far slower, more physically demanding work of excavation on the ground.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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