The Kelimutu National Park in Flores island in the NTT province of Indonesia, features a 3 colored crater lake that changes color rather often.
At the time of the nation's independence (1945), the three lakes were white, red, and blue in color. Now, they are black, brown, and green.
The lakes are separated by a very thin and steep cliff of rock that is rich in minerals, and the whole national park is full of exotic biodiversity nestled in a very natural rainforest setting.
The volcano contains three striking summit crater lakes of varying colors. Tiwu Ata Mbupu (Lake of Old People) is usually blue and is the westernmost of the three lakes. The other two lakes, Tiwu Nuwa Muri Koo Fai (Lake of Young Men and Maidens) and Tiwu Ata Polo (Bewitched or Enchanted Lake) are separated by a shared crater wall and are typically green or red respectively. The lake colors vary on a periodic basis. Subaqueous fumaroles are the probable cause of active upwelling that occurs at the two eastern lakes.
Kelimutu is also of interest to geologists because the three lakes are different colors yet are at the crest of the same volcano.[ According to the local officer at Kelimutu National Park, the colour changes as a result of chemical reactions resulting from the minerals contained in the lake perhaps triggered by volcano gas activity.Kawah Putih lake in West Java, south of Bandung, is another crater lake in Indonesia with some similarities to the lakes at Kelimutu.