Ambang Mountain is a nature reserve that lies in the north of Sulawesi Island that covering 3.232 hectare.
This is a complex of volcanoes at the western of the northern arm of Sulawesi and there are two lakes, lake Mo'oat and lake Tondok (Danau Mo'oat and danau Tondok), at an elevation of 750 m. The larger of the two lakes is Mo'oat. Both of them are side by side. The volcano contains several craters up to 400 m in diameter and five solfatara fields. The only historical account of its eruption occurred somewhere in the 1850s.

Ambang nature reserve is situated close to the equator in the mountainous area, precisely to the east of Bogani Nani Wartabone National Park. The lower parts are covered by evergreen rainforest with few palms and a canopy of up to 25 m with some emergent trees. There are a number of marshes and small lakes and, particularly near the edge of the park, trees have been felled and there are clearings and the growth of secondary forest.

The reserve is best accessed from the village of Singsingon, which is an hour's drive from Kotamobagu. Visitors need a permit to visit the park and these can be obtained from the National Park Office in Kotamobagu. The village can be reached by a crowded public, then from the centre of Kotamobagu or alternatively one can charter a bus direct to the village for a more comfortable ride.

In addition to the fauna that live in this Mountain, there are a number of mammals in the reserve although these face hunting pressure, with traps being set, mostly for small mammals. The Celebes crested macaque is found in the reserve and the spectral tarsier is also present but both of these are very wary of humans. Rare mammals include the anoa, the Celebes warty pig, the Sulawesi bear cuscusand the Sulawesi dwarf cuscus, and there are plenty of forest rats which emerge into the open at night.