350 at the Shore Temple in Mahabalipuram
A group of Indian, European and American tourists spoke to other visitors and to each other about 350 and about the threats to Mahabalipuram and other coastal heritage sites -- not to mention coastal zones in India as a whole. They demonstrated 350 in front of the Shore Temple, an UNESCO World Heritage site, and is believed to be the oldest structural temple in South India (as opposed to the many other temples in Mahabalipuram that are carved from one single rock).
The Shore Temple is also significant as it was rediscovered after having been submerged underwater for hundreds of years. Mahabalipuram is a town of many temples cut from single rocks in the seventh century, and reports from British traveller John Goldingham who visited the town in 1798, described "Seven Pagodas" by the sea. It was uncovered after the 2004 tsunami removed much of the sand that had been hiding the Shore Temple for so many years. It is believed that there are six other such temples (to make the Seven Pagoads) still underwater, and it is a heritage site worth protecting!
Sea level rise is threatening it and other such coastal monuments.