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.
Tamu Massif
Tamu Massif is an extinct submarine shield volcano located in the northwestern Pacific Ocean. The possibility of its nature as a single volcano was announced on 5 September 2013, which, if corroborated, would make Tamu Massif the largest known volcano on Earth. It is located in the Shatsky Rise about east of Japan. Its summit lies about below the surface of the ocean, and its base extends to a depth of about . The volcano is about tall.