Geyser
Yellowstone is the largest geyser locale, containing thousands of hot springs, and approximately 300 to 500 geysers. It is home to half of the world's total number of geysers in its nine geyser basins. It is located mostly in Wyoming, USA, with small portions in Montana and Idaho. Yellowstone includes the world's tallest active geyser (Steamboat Geyser in Norris Geyser Basin), as well as the renowned Old Faithful Geyser, Beehive Geyser, Giantess Geyser, Lion Geyser, Plume Geyser, Aurum Geyser, Castle Geyser, Sawmill Geyser, Grand Geyser, Oblong Geyser, Giant Geyser, Daisy Geyser, Grotto Geyser, the Fan & Mortar Geysers, & the Riverside Geyser, all in the Upper Geyser Basin which alone contains nearly 180 geysers.
Southern Peninsula (Iceland)
The Reykjanes Volcano is a large volcano covering the Reykjanes Peninsula in Iceland, where the Mid-Atlantic Ridge rises above sea level. The volcanic system consists of lava fields, postglacial basaltic crater rows, and small shield volcanoes. The submarine Reykjaneshryggur volcanic system is contiguous and is considered part of the Reykjanes volcanic system, which is the westernmost of a series of four closely spaced en-echelon fissure systems they extend across the Reykjanes Peninsula. The highest of the system's multiple vents is 230 metres (754 ft). Dredging operations resulted in recovery of basaltic rocks of probable Holocene age. Most of the subaerial part of the system is covered by Holocene-age lava fields. During the 13th century, subaerial eruptions occurred on the fissure system along the Reykjanes fissure system. Tephra deposits from Holocene eruptions have been preserved on the Reykjanes Peninsula.