Three volcanic crater lakes at the summit of Kelimutu on Flores Island, each a different color — combinations of turquoise, dark green, black, blood-red, and deep blue — that change independently of one another on timescales of months to years.
At the summit of Mount Kelimutu on the island of Flores, three volcanic crater lakes sit within a few hundred meters of each other. Each is a different color. The colors are not fixed.
Tiwu Ata Mbupu — Lake of Old People — has appeared in shades of blue, blue-green, and deep teal. Tiwu Ko'o Fai Nuwa Muri — Lake of Young Men and Maidens — has been turquoise, then green, then dark brown. Tiwu Ata Polo — Enchanted Lake — has cycled through blood-red, black, and deep blue-green. The three lakes change color independently of each other, on timescales ranging from months to years.
The chemistry behind the changes is understood in broad terms. The lakes sit above hydrothermal systems that introduce different gases, minerals, and dissolved ions — sulfur compounds, iron, silica — at varying rates. The ratio of oxidizing to reducing conditions in each lake, the pH, the suspended mineral particles: all interact to produce the apparent color. Minor changes in volcanic activity alter these ratios; the color shifts accordingly.
The Lio people of Flores have a different explanation. The lakes are the afterlife of the dead: old people rest in the blue lake, young people in the turquoise one, the wicked in the dark red one. Ceremonies are held at the rim each year. The colors are not phenomena to be explained but messages to be read.
From the summit at dawn, in the mist before the clouds burn off, with three lakes of three different colors visible in the craters below — the chemical explanation is available and accurate, and it explains nothing about what it feels like to be there.