According to scientists the changes are caused by geological and chemical processes in the bottom of the lakes. It could also be a result from refraction of the sunlight, the bacteria populations and the chemicals that are dissolved in the water.

Kelimutu has been denoted as one of the National Parks and is 5300 hectares in size, known as Kelimutu National Park. It is surrounded by forests with rare flora and fauna such as palm trees, pine, mountain fig (casuarina yunghuniana), red wood (pterocarpus sp), edelweiss, hog (sus vitatus), javan porcupine (hystrix javanica), the giant rat (papagomys armandvellei), monkey (macaca fascicularis) and gerugiwa (kind of bird). Being a natural reserve, this park is a popular tourist destination.

Moni Village

Moni village is set out along the length of the road that runs from Ende, northeast to Maumere. It's full of losmen and restaurants, but is still a relaxed place to spend a few days, with great walking in the surrounding hills. Behind the Amina Moe losmen and opposite the market is a rumah adat, where occasional evening dance performances are held (Rp3000) and traders hang around trying to sell ikat. There is no bank, in Moni.

Climbing Mount Kelimutu

The starting point for the climb of mount Kelimutu is Moni, a village along the main road from Ende to Maumere. In the 1970's the lakes were only reachable by foot or by horse. You had to start at two in the morning; it's a heavy trip which takes about three to four hours to reach the summit. Only fanatic people do it this way, mainly by horse, which is a bigger torture than walking when you don't have a saddle. Take a guide with you. Besides nights with full moon, chances of getting lost are big.

By truck - Every morning around 4am an open-sided truck takes 'climbers' from Moni up to Kelimutu, a trip of about 45 minutes, returning at about 7am (Rp10,000 one way, minimum five people, plus Rp1000 park fee).

You ought to be at the viewpoint around 5.30, the place is an ugly concrete slab which can be reached via a concrete stairs. It can be cold there, bring along warm clothes and maybe some warm coffee or thee. The best view is from the south crater rim, looking north over the two sister lakes; the trails that run around other rims are extremely dangerous - tourists have disappeared up here. A much nicer alternative to returning with the truck is to walk back down to Moni, which takes about three hours, with rolling grassy meadows flanking extinct volcanic hills, and views all the way to the sea. Practically the whole walk is downhill, but always bring water and wear good boots. A shortcut by the PHPA post cuts off a good 4km from the road route, takes you through some charming local villages and past the waterfall (air terjun) less than 1 km from central Moni, which is a great spot for a dip after what can be a very hot walk. A little further down is a hot spring, the perfect place to soak weary feet.