Kelimutu

On the eastern end of Flores island, three crater lakes sit almost side by side at the 1,639-metre summit of Kelimutu volcano, and each one keeps a different colour from its neighbours. Local Lio tradition names them Tiwu Ata Bupu, the Lake of Old People, usually blue; Tiwu Nuwa Muri Koo Fai, the Lake of Young Men and Maidens, typically green; and Tiwu Ata Polo, the Bewitched or Enchanted Lake, usually red. The colours are not fixed: over the decades since they were first recorded, each lake has cycled through shades of turquoise, brown, black and white, sometimes changing within the same year. The mechanism is chemical rather than decorative. Subaqueous fumaroles beneath each lake release volcanic gases, chiefly sulfur dioxide and hydrogen sulfide, and the resulting oxidation-reduction reactions shift dissolved minerals between different coloured states. Acidity varies enormously between the three lakes and over time, with recorded pH levels as low as 0.5 in the most acidic. Because each lake sits in its own separate crater with its own plumbing, they change independently of one another rather than in sync, which is part of why the site draws repeat visitors and long-term researchers alike, including monitoring linked to the Smithsonian Institution's Global Volcanism Program. Kelimutu sits inside Kelimutu National Park in Ende Regency, East Nusa Tenggara province, about 50 kilometres east of the regional city of Ende. Most visitors fly into Ende or the larger airport at Maumere, then drive roughly three hours to the small hillside town of Moni, the usual overnight base. From Moni it is about 45 minutes further by road to the park's vehicle park, followed by a short, well-maintained walk to the viewpoint overlooking all three lakes. Sunrise is the customary time to go: cloud tends to build over the crater rim as the morning goes on, and the low light is when the colours read most clearly against the pale volcanic rock.