is a stalagmite/stalactite cave in To Nae Mountain near Ban Chao Mai. It can be reached by boat from Yao Beach onto Khlong Caho Mai for about 15 minutes. A small rowboat can go through the cave to a verdant mangrove forest where the cave is nearby. Visitions have to walk up to the cave to fully appreciate its beauty.
A not-to-be-missed attraction would be Tham Morakot (Emerald Cave), which is indeed a beautiful limestone tunnel that can be entered by boat during low tide. Moreover, it is named Emerald Cave for a reason; the tunnel stretches 80m before finally emerging into an open pool of emerald hue! It is truly an awesome sight. The southern end of the island presents the beautiful Ao Phangkha and the fishing village of Hua Laem.
The most beautiful island in Hat Jao Mai National Park is Koh Kradan. Only five out of six precincts belong to the park, while the other is used for coconut and rubber plantations.
The water on both islands is so clear that the sea bottom can even be seen from the surface. This encourages the growth of corals and healthy reefs along the northern side of the islands. The water is also shallow enough for snorkeling. Although there are fewer white-sand beaches on Koh Kradan than on Koh Muk, the coral reef on the side facing Koh Muk make up for good diving. Koh Cheuak and Koh Waen are small islands between Koh Muk, Koh Kradan and the Trang coast. Like the Emerald Cave, Koh Cheuak also has a small cave that can be entered by boats at low tide.
this picture is from : Ianz