Lake Kelimutu is an iconic volcanic lake at the summit of Mount Kelimutu, Ende, Flores Island. Known as the “Three-Colored Lake,” it features three craters (Tiwu Ata Mbupu, Tiwu Nuwa Muri Koo Fai, and Tiwu Ata Polo) whose waters mysteriously change color due to chemical reactions between gases and minerals.