This is located a few Kms outside of Ao Nang and a Tuk Tuk there and back will cost about B400..  

 According to Lonely Planet Thailand Guide (2009), entrance fee is B50pp however it is B200pp (B100 for children). 

The appraoch down some steps has the usual souvenir vendors, There are a few fossil beaches in the area, all very similar in nature. The main area itself, located at the entrance point, is basically a very small beach which looks as though its covered in broken concrete slabs, which on closer examination are in fact the gastropod fossils embedded in a fossilised layer. 

 There isnt actually a huge amount to see or do and for money, unless you are a major fossil fan, there are almost certainly better ways to spend your time and money.