Kamchatka, Russia
Kamchatka is a peninsula located in the far east of Russia and is part of the regions of the Russian Federation, this huge peninsula is 1,250 km long and has an area of 472,300 km².U Peace ocean near its coast lies a giant sea Kuril-Kamchatka Trench, 10,500 meters deep . In the middle of the peninsula is the famous Valley of Geysers. Valley of Geysers is one of the largest gareas in the world and the only one in Eurasia. In this valley, 6 km long, is located about 90 geysers and many hot springs, mainly on the left side of the river . The largest geyser is the Vejkon, which pushes hot water and steam 49 m and up to four minutes every hour. All geysers feed ground water and that are up to 500 meters below the surface, and their temperatures reach 250 ° C.
I believe that Kamchatka has the world’s greatest concentration of active volcanoes. This activity has everything to do with the sea trench you mention, as this is a major tectonic subduction zone.