India, Aug. 1 -- What does it take to find a hero stone?

Amid increased efforts to document these tiny memorials, particularly across Tamil Nadu, archaeologists, scholars and volunteers are undertaking what are essentially modern-day treasure hunts. They wade through dense forests, trek across arid wastelands and wander through urban construction debris, looking for signs of a memorial to a fallen hero.

Each memorial is tangible proof of a different time, a different tongue, a different people and a different way of life, says Sudhakar Nalliyappan, a heritage conservationist and founder of the NGO Yaakkai Heritage Trust.

Nalliyappan leads a collective of 50 people, including archaeologists, historians and volunteers, who are currently ...