The steam vents are exactly what they sound like - portions of land where steam is being vented from underground water. Its a bit like a miniature Yellowstone minus the geysers and water pools!

There is an overlook along the edge of the Kilauea Caldera called the Steaming Bluff where there are a number of vents. The view includes the currently active portion of Kilauea although no lava was visible today. There is also a short trail which passes by a number of other vents and can be combined with other trails to return to the parking area. These trails pass through some really lush green areas!