Mount Gahinga (3,474m) is the smallest of the Virunga volcanoes. Mount Gahinga is known as the guide, and the Batwa used to look for its high peak to help orient them in the forest. Gahinga has a crystal clear crater lake about 36m wide at its summit. The top commands panoramic views far into Uganda, Rwanda and along the length of the Virunga chain. It is named after the local practice of tidying the volcanic debris that clutters local farmland into neat cairns - or gahinga. Its swamp filled crater is around 180m wide.

Apart from the numerous streams flowing northwards from the mountains, there is a crater lake and a swamp crater on Mount Gahinga summit. There are also swamps in the saddles between the three volcanoes that retain water all year round, while the plains at the foot of the volcanoes are characterized by deep volcanic ash, and run-off from the mountains rapidly disappears underground.

The main source of the north-flowing surface water is the Kabiranyuma swamp in the Mount Muhabura - Gahinga saddle. River Kabiranyuma drains the swamp and is an important source of water for the populations around. It is the only river that does not dry up completely in the driest months of June to August. River Ntebeko drains the Rugezi Swamp in the Gahinga - Sabinyo saddle northwards to the Democratic Republic of Congo, while Nyabirerema stream drains Mount Sabinyo northwards to Democratic Republic of Congo.

Mgahinga area is characterized by two rainfall seasons (March to April and September to December) and two dry seasons (January to February and May to August). The Virungas generally receive higher rainfall than the surrounding areas. Mgahinga is frequently shrouded in mist and humidity is high. Temperatures generally range from 4 degrees Celsius at the highest elevations to 18 degrees Celsius at the lowest points. The tops often reach freezing points and hailstorms are common.

The Batwa culture is particularly intimately bound to Mgahinga Forest and its surrounding areas. To the Batwa the area signified a source of physical, emotional and spiritual well-being. The caves in the park were important spiritual and cultural sites for them, and a few still visit them. Hikers can also be part of birding activities in Mgahinga after hiking Mountain Gahinga. There are several bird species that can be spotted in the thick vegetation in these two national parks. To have the best of birding, you will need to come along with a birding book and a pair of binoculars.