Mbeli Bai, Forest clearing in Nouabalé-Ndoki National Park, Republic of the Congo.

Mbeli Bai is a permanently flooded freshwater swamp clearing of 12.9 hectares in the south-west of Nouabalé-Ndoki National Park, the largest of the swamps near the Ndoki River. It lies at 300 m altitude, crossed by streams and pools, and carries a floating mat of semi-aquatic sedges and grasses. The surrounding forest is dominated by Gilbertiodendron dewevrei.

In 1993 the Wildlife Conservation Society and Congo's Ministry of Forest Economy and Environment protected the swamp from human settlement, and WCS researchers began a pilot study there. The permanent Mbeli Bai Study was set up shortly afterwards, and since February 1995 it has monitored the clearing's gorillas continuously from a 9-metre observation platform.

The camp relies on local staff: a tracker and two cooks are always employed, and some of them formerly hunted in the area, so the jobs offer an alternative income. Congolese and international staff also train local students to assist with the research, and volunteers from other countries work at the bai.

Visitors observe the gorillas from an elevated viewing platform while maintaining a respectful distance from the animals. A guide is required to access the site and help you understand the gorillas' behaviors and movements throughout the day.

The gorillas visit this clearing specifically to access minerals found in the water and plants that are scarce elsewhere in the forest. This natural behavior makes the site an exceptional place to watch how they feed and interact.