A very nice town about four hours by bus from Chennai. There is a very important temple, the Arunachaleswar, in town and so it is filled with pilgrims. It is a very relaxed place that kind of reminded me of the Shwedagon Pagoda in Yangon, though with a definite Hindu feel to it. The pilgrims were very friendly and eager to talk to me and be photographed. Many of the men were all in black and the women in red. There were fires burning at many of the shrines and there was an elephant on hand to annoint you on the head if you were so inclined. The hotels are nice and dirt cheap.
My first day in town I spent at the temple. The next day I climbed halfway up the mountain just behind it and then went and rented a motorbike out by the ashrams (there seem to be dozens and there were quite literally hundreds of westerners staying at them. I've never seen so many westerners in sadhu garb) and went riding through some villages. A very nice day that. I could easily have spent several days in Tiruvannamalai, but, alas, there are other temple towns to see. But I will say it is now on my list of all-time great temple towns, along with Madurai, Kandy, and Luang Prabang.