Phu Pha Phet Cave is the largest cave in Thailand and the fourth in the world, with an interior area of more than 80,000 square meters divided into nearly 20 chambers, and each chamber is named based on the shape of the stalactites, such as the Diamond Curtain Room, Coral Room, etc. It is one of the Sutton Geographical Gardens that dates back more than 400 million years, and inside it stalagmites sparkle when exposed to light like diamonds.