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.
Tham Phraya Nakhon Cave can be reached on foot from Laem Sala beach inside the park. The rather steep and rocky ascent up the side of the mountain (about 430 meters long) provides spectacular sea views and takes about 30 minutes.
Tham Phraya Nakhon is actually two sinkholes whose roof has fallen in, letting in sunlight. In the middle of the cave is a Thai-style pavilion built for a visit by King Rama V in 1896. The cave was named for Phraya Nakhon, ruler of the city-state of Nakhon Si Thammarat, who inadvertently discovered it over 200 years ago when a gale forced his ship ashore.
Phraya Nakhon Cave can be reached from Laem Sala Beach, by a steep rocky trail, 430 m. long and rising to a height of 130m., taking about 30 minute to climb. Caution should be used and proper footwear worn as the rock is sharp and can be slippery.