Volcano Tours on Hawai'i: The Hawaiian Islands are not only home to the most active volcanoes in the world, Kilauea and Mauna Loa on the Big Island, but also boast a unique natural environment. Born by volcanic activity of a very active hot spot in the middle of the Pacific Plate, they are a showcase of natural history.

Ijen volcano photos: Ijen volcano in East Java is famous for its turquoise acid crater lake and the large sulfur deposits that are being mined by local workers. At night, the scene is illuminated by ghostly blue flames, as sulfur ignites.

Bromo volcano photos: Bromo is one of Indonesia's most visited volcanoes. It is the most active vent inside the huge Tengger caldera and erupts every few years.