The Kuril Islands form a volcanic island archipelago that stretches approximately 1,300 km northeast from Hokkaido, Japan, to Kamchatka, Russia. The 56 islands chain has around 100 volcanoes, some 40 of which are active.
Twig Stairs (source: Imagination in Metals)
Kelimutu is a volcano, close to the small town of Moni in central Flores island in Indonesia. The volcano contains three striking summit crater lakes of varying colors. Tiwu Ata Bupu (Lake of Old People) is usually blue and is the westernmost of the three lakes. The other two lakes are separated by a shared crater wall and are typically green or red. But their color can vary unpredictably between blue, green, black and red.