A Miocene-age canyon in Villupuram is a repository of centuries of geological data

The Bommayapalayam Canyon is part of a range of ravines skirting the Auroville bio-region. They were formed over centuries of downcutting by water currents of the monsoon rain ferrying topsoil and rock fragments to the Bay of Bengal. The Tamil Nadu government plans to protect the canyon, declaring it a geo-heritage site