The Hot Spring:
Pahoa Steam Caves is a very magical place in the jungle just a couple hundred feet from the highway. The area is completely natural in the Keauohana Forest Reserve with the only additions being wooden planks for sitting or changing. The natural jungle has made this location clothing optional, unlike the other springs in Hawaii. This could be because the local visitors are mostly hippies, instead of surfers or families. The caves have existed for many years but steam only started emerging in and around the caves after the volcanic activity in the east rift zone of the Kilauea volcano changed in the early 1950's. Groundwater is superheated by underground lava chambers and becomes steam. Some people are concerned there are dangerous amounts of volcanic gases but because the steam is from groundwater (not the lava itself) it is completely safe.
The hottest cave is the furthest away from the road in old caved-in basalt "splatter cone". The steam is nice and hot, around 150 degrees F or feeling like 105 degrees F in water temperatures. The cave is accessible with a little wooden ladder, has two small benches to sit on, and can fit 3-4 people. The cave closest to the road is the largest but is considerably cooler with what feels like 101 degrees F in water temperature. About 9 people can fit in the cave comfortably on the two large benches and light gets into the cave from a hole in the top that is covered by a clear tarp. Several other small open air vents, large enough for one person, are located around as well. In a couple there are wooden planks on the ground to sit on in front of the vent for someone to enjoy the steam.
The caves are open all the time with a small pull out area on the highway to park in. Care should be taken at night because there is no lighting and the ground is often wet and slippery (it rains in this area all year round) and the rocks are very sharp. Vandalism and break-ins are also very common in the parking area so no valuables should be left in the car night or day. The Pahoa County was trying to buy the poperty but decided not to in March 2011. Someone died in the steam caves and the owner decided to close the property to the public to protect himself from prosecution.