Tham Sin is another cave that can be reached via the same route as Tham Khu Ha Phi Muk, for one km. further, then turn left for another km. passing the Ban Tham Sin School. On the left is a small trek leading to a hill next to the road. The cave is 28 metres high above the ground with steps leading to the entrance. This is a very small and dark cave with ancient mural of different postures of the Lord Buddha and a painting of three women standing together on the cave wall that has deteriorated with time. The mural was assumed to be of late Srivijaya Period, around the 14^th – 15^th centuries. A torch or a lamp is highly recommended to view the mural and the cave itself.