Koh Rok is a verdant island with tropical forest and mangroves and even a jungle with huge banyan trees. The most famous beach of Koh Rok Nok is Ao Man Sai beach, a little further away is another beach called Ao Tha Lu beach surrounded by black limestone cliffs. In Koh Rok Nai, the most beautiful beach is probably Ao Sarn Chao (Spirit House Beach). The fishermen built spiritual houses to protect their ships. While south of this island, stands the post that marks the end of the Thai land. With crystal clear waters and avisibility up to 20 meters and corals still relatively untouched, Koh Rok is a great destination for scuba diving and snorkeling (Bermuda Ridge and Seafan Garden are the best snorkeling spots).
There is no accommodation in Koh Rok but you can rent a tent from the rangers of Thailand National Parks on the island (300-700 THB per night). They also have a few bungalows around 2000 THB per night. Online booking available on national parks website.