Seeing through the trees
The Kumano Kodo is a network of ancient pilgrimage trails crossing the dense forests of Japan's Kii Peninsula. For centuries, people from all levels of society have walked these paths to reach the three grand shrines of Kumano: Kumano Hongu Taisha, Kumano Hayatama Taisha, and Kumano Nachi Taisha. While the main routes are well-known and form part of a UNESCO World Heritage site, the thick forest canopy has long hidden the full extent of this medieval network. Traditional ground surveys are slow and difficult in the steep, rugged terrain.
To overcome this, researchers from the Wakayama Prefectural Board of Education's Center for Cultural Heritage used airborne LiDAR (Light Detection and Ranging). This remote-sensing method involves an aircraft firing millions of laser pulses toward the ground. By measuring the time it takes for these pulses to return, a precise and detailed 3D model of the ground surface can be created. The technology effectively filters out vegetation, showing subtle features on the forest floor that are invisible to the naked eye. This digital deforestation allows archaeologists to map vast, inaccessible areas with incredible accuracy.