Kamchatka carries more than 300 volcanoes on one peninsula hanging off the Russian Far East into the Pacific, twenty-nine of them still active, and the ground here has never settled. The Pacific plate dives under the edge of Asia at about eight centimetres a year, one of the fastest rates anywhere, and that is what feeds the cones and drives the boiling water. Almost none of it has roads. Avachinsky stands over Petropavlovsk-Kamchatsky, the one city of any size. A full day on loose scree gets you to a steaming crater rim, with the bay and the Pacific below. Everything beyond the city you reach by helicopter, over snow-dappled tundra and rows of cones, caldera lakes and lava flows that no road could show. Around Tolbachik the lava plains are so black and bare that Soviet engineers tested lunar rovers on them, and the 2012 eruption laid a fresh sheet over them.
The bears are the other reason to come. Kamchatka holds around 15,000 brown bears, the densest population on Earth, and most of them work Kuril Lake, where between two and six million sockeye push in to spawn each year. From a raised platform you can have a dozen in view at once, close enough to hear the splash. Boats run the Pacific coast under green slopes that drop straight into the ocean, past sea stacks and cliffs loud with puffins, sea otters on the water below. The Valley of Geysers is another flight: a steaming green canyon walked on boardwalks, where jets of boiling water come out of the ground on their own timetable and hot streams run past your feet. In June 2007 twenty million cubic metres of rock came down that valley in minutes, damming the river and drowning several geysers under a new lake. The biggest, Velikan, was missed; the water later fell, and the buried vents came back through the debris.