The 75 million-year-old Shell Cemetery in Krabi province has some of the oldest shellfish fossils on earth. Although not immediately impressive - the site looks as though it houses a number of concrete blocks - closer inspection proves more rewarding.
The blocks you see are in fact thousands of shells stuck together to form a solid mass about 200 meters wide and 50 meters thick. Apparently, most of the shells are Gastropods and the blocks are formed from lignite deposits. If you are especially interested in the earth's prehistory, this will be a great place for you to visit. This is still somewhere worth visiting even if you are not.
Details: This is a National Park. The admission fee is 200 Baht for adults and 100 Baht for children.
How to get there: The 'Shell Cemetery' is 19 kilometres west of Krabi. To get there take a Songtaew from Maharat Road in Krabi. The trip costs around 40 Baht.