Better known as Rabbit Island, Kaoh Tonsay is a lovely little island about 25 minutes away from Kep by hired boat, making it one of the most easily accessible of all the islands. It is also one of the least-developed, with no motor vehicles, no mains electricity and few residents, making it an ideal getaway from the grind. Definitely not flashpacking, Koh Tonsay will float your boat if you appreciate a good sunset.
It’s also worth keeping an eye out for occasional jellyfish and spiky sea anemones that will spoil your fun (although your friends will probably love an opportunity to try out pee-related first aid remedies).
You can also head out to Koh Svay (Mango Island) or Koh Pos (Snake Island). Koh Pos has a white sandy beach flanked by a small Cambodian fishing village. If you want to escape the crowds on Koh Tonsay, which does get busy, this is a nice retreat. It is, like many Cambodian beaches, quite litter-strewn however. You can hire snorkelling gear on Koh Tonsay to bring along, and we’re told that the snorkelling here is lovely.
Map : https://goo.gl/maps/pqFXuEvXJW4MyK3V8