What you are looking at is actually the river bed of Mae Khong river, which fills in the month September. When the river withdraws the rock structures (Sam Phan bok = 3000 holes) become visible that have been formed already 110.000.000 years ago. It is a fascinating landscape and of course people see all sorts of significance in the shapes, meaning a Mickey Mouse hole, a heart, the number 800, the Grand Canyon etc. See what you want to see and enjoy he unusual shapes. There is no entrance fee. Although it is walkable I would recommend taking a pick-up (200 baht for the whole car) and we were joined by a sweet 7-year old (!) guide who gave a very good explanation, albeit only in Thai. You can tip whatever you like, we gave 100 baht which was probably over-generous, but it is lovely to see this young enterprise.

We thoroughly enjoyed our visit to Sam Phan Bok. We hired a boat that took us to several spots along the river. Boat rentals run from a few hundred baht to 2,700 baht, depending on the destinations and duration. As noted by others, there are lots of fun shapes of the holes and pools in the rocks. The entire area goes under water when the water level in the river rises in rainy season, but we were there in May and it was still very good. The young boy working with the boat operator knew where all the interesting rock formations were and was an expert at positioning us for fantastic photos, including unique reflections and framing by the rocks. The current in the Mekong River is very strong and the water is deep; be sure to wear a life vest when boating.

There is a choice of walking to the boulders or taking a ride in a pick up which will cost 200 THB for a round trip. There is some climbing involved so be careful. Once at the rocks there are guilds for hire. The famous formation are Mickey mouse which was easy to find, Heart and number 800.