The Fish River is the longest interior river in Namibia. It cuts deep into the plateau which is today dry, stony and sparsely covered with hardy drought-resistant plants. The river flows intermittently, usually flooding in late summer; the rest of the year it becomes a chain of long narrow pools. At the lower end of the Fish River Canyon, the hot springs resort of Ai-Ais is situated.
Public view points are near Hobas, a camp site 70 km north of Ai-Ais. This part of the canyon is part of the Ai-Ais/Richtersveld Transfrontier Park. The other 90km of this canyon are privately owned.
Upstream the river runs through horizontal dolomite strata. These strata formed part of the canyon about 650 million years ago when plate movement cracked the earth, the first process in the formation of the Fish River Canyon.
Lower down, a granite complex system is exposed to form a characteristic river bed that results in forms like Fingerspitze. In this area, a fault runs north-south, which accounts for the gorge-like channel and the presence of hot sulphurous springs.
The Fish River Hiking Trail starts at Hobas and ends 85 kilometres (53 miles) further south at Ai Ais. No facilities are available and hikers sleep outdoors for the entire trip which usually takes 3 to 5 days to complete.
Due to high summer temperatures which frequently exceed 45°C, the hike is only open in winter. The season starts 15 April and ends 15 September (winter time in the Southern Hemisphere). A medical certificate is required to attempt the hike, and groups must consist of at least 3 participants.
- Ai-Ais/Richtersveld Transfrontier Park