We did a 3 day trek out of Thakek to Konglor cave. The cave is amazing!!! It’s 7.5 km long and you travel through the cave by longtail (boat). It is so enormous! At points the roof is too high for your torch to reach. You could build an entire city inside. At certain points we got out and hiked up underground hills to see stalagtites and stalagmites. Unfortunately I no digi camera. Only film.