Heres a couple of pix from our trip up north to Ryusen cave. This is the 3rd cave I've visited in Japan. It's Japan's deepest water cave (150m deep) and has the clearest water in the world.
this section was only about 35m deep but super nice.
The cave is in north japan, just below Hokkaido island. its thought to be about 5km long as it hasn't fully been explored yet. visitors though only walk about 200m through the cave. the water is totally drinkable and for sale everywhere around the area. walking through the cave is like being in a big refrigerator, but a nice change from the hot muggy weather outside. being the Obon holidays it was packed, so it was hard to set up my tripod to get the shots i wanted. after here we made the long drive home which took about 8 hours, most of the way in shitty traffic jams.