Not to be missed is the spectacular Tham Lod cave complex, which has many features that make it one of the "must see" caves in the entire SE Asian region. At 50 metres in height, Tham Lod has the largest cave opening in SE Asia with a river passing through, and contains amazing limestone stalactite and stalagmite formations along its 1.7km length. Tham Lod cave is also famous for a spectacular sight every day at sundown. If you stand just outside the exit, you will see thousands of swifts swarm into the cave for the night, followed by a similar number of bats exiting. The Nam Lang river flows through more than a third of the cave and affords the opportunity for you to float through the cave on rafts, where you can also stop and climb through various caverns and visit 'Phi Man cave'.This cavern contains prehistoric teakwood coffins, thought to have been carved by members of the Lawa tribes, many thousands of years ago. During and just after the rainy season, it is even possible to take a hair-raising kayaking trip through the cave although when the water is very high. During this high-water period, it may not be possible to go to certain areas of the cave complex. Entry to Tham Lod: 150B for guide (compulsory) for up to three people. One way raft trip 300B; (walk back, 15 mins) or round trip, 400B Getting Here: It is easily accessible from Soppong, at the end of a short track from the village. If you are a cave enthusiast, you might also want to check out Cave Lodge Guesthouse & Adventure Tours www.cavelodge.com, which is located near the caves and specialises in cave tours and other adventure activities in the surrounding countryside. Other large caves in the area include: Tham Mae Lana, (12km), Tham Nam Lang, (8.5km), Tham Bung Hu, (4.4km), Tham Pha Mon ,(4.1km), Tham Seua/Tham Lom, (3.1km), Tham Susa, (2.6 km), Tham Huai Kun, (1.7km), Tham Pang Kham, (1.4km) and Tham Plah, (1.4km).