Gisenyi (now officially called Rubavu) sits at the northern end of Lake Kivu on Rwanda's western border, directly across from the Congolese city of Goma. It's the main launch point for excursions to Volcanoes National Park, where mountain gorillas roam the forested slopes of the Virunga volcanoes — and light aircraft flights over the volcanic craters leave from here too.
The town itself is pleasant and unhurried, with a lakeside promenade and beaches that are popular with Rwandans on weekends. Lake Kivu offers swimming, kayaking, and boat trips to small islands. The setting is striking: the lake is hemmed in by steep green hills, and on a clear day Nyiragongo's cone is visible smoking across the border.
The Congo Nile Trail — a 227-kilometre hiking and cycling route along the lake's shore — begins in Gisenyi and runs south to Rusizi, passing through coffee- and tea-growing country that few tourists see. The Rubona Peninsula south of town makes a pleasant half-day walk with good lake views.