Near Ao Phra Nang, those with an interest in geology should head to the Susaan Hoi (the fossil shell cemetery), where strange dark sheets similar in appearance to fragments of tarmac can be seen at the bottom of a cliff. As you approach along the path descending to the beach, fossil beds, made up of shells 75 million years old, come into view. This extraordinary geological site is one of just three of its kind found around the world (the other two are in Japan and the United States).