I visited Mahabalipuram in the first day of my visit in India in March 2015. I went there by taxi from Chennai airport (approx. 2200 INR for return trip to the city center), but there is very good system of cheap public buses from Chennai.

The site itself was nice but, comparing to other WHS in Southern India, not so deligthful. The sites is not big, but there is some distance from Shore Temple to Five Rathas. The latter I liked the most, especially because there were a lot of school children in uniforms, running and climbing the stairs and statues. The surroundings of the Shore Temple were, to my regret, not so beautiful and the beach was full of litter.