Elephant Island is one of the most important islands in Thailand, and a good place to spend a few days visiting and lazing around.
My suggestion
Be careful where you stay, lost of the places to stay on the beaches are noisy, you would be better off choosing places on the creeks or smaller sites.
The Khong Chiam region is still largely unaffected by tourism and, for those willing to explore it, offers spectacular scenery and the promise of peaceful days spent well away from the noise and chaos of the urban environment. With its waterfalls, cliffs and rock paintings, Pha Taem is the kind of place you simply never tire of exploring.
Elephant rides have become a major concern in many locations, but are still offered by a handful of so-called "sanctuaries" with the proposition to get close to the exotic and majestic animal. Elephant rides are offered on every street corner and Westerners have little knowledge about the cruel methods to succeed in training these enormous animals.
To set the scene for you, imagine 2,188 km² covered by 80% forest and populated with more than 800 animal species roaming completely free. Add streams, waterfalls and a mountain range amongst 2,000 plant species. Classify it all as a UNESCO world heritage site and you have the Khao Yai national park.