The nature reserve of Khao Sam Yot National Park is huge and there are plenty of fantastic places to see, but Phraya Nakhon Cave is a place you should visit at least once in your lifetime. You will have to climb 1400 feet up a mountain, between the trees, and then a fairly high staircase. It’s not an easy walk, but it’ll be worth your while. You’ll find a unique cave where the light from the sun shines on a hidden temple.