This is one of the most visited tourist spots in Thailand: known from the movie "The Beach" with Leonardo DiCabrio, and still a unique beauty: Maya Bay on Phi Phi Island.
Due to the large streams of visitors in the past few decades, however, nature has suffered so much that access has now been restricted. Boats can no longer drive directly into the bay, but have to drop their guests off at another location so that they can then walk to the dream bay via a footpath. Apart from taking pictures, there isn't much else to do - swimming is forbidden, and lying on the beach between snapping crowds is rather uncomfortable.
The entry to this area is 400 THB / Adult, which have to be paid cash to the Park Rangers. There are different rates for Thai nationals, foreigners, adults and kids.
Please note: In some areas additional park fees have to be payed cash to the Park Ranger. Due to the double pricing system it might be different for nationals and non-nationals.