Ghar Boumâaza, Cave system in Tlemcen Province, Algeria

Ghar Boumâaza is a cave system and karst spring near Sebdou in Tlemcen Province, Algeria. It forms the outlet of the Tafna River's underground course, with passages that run for about 11 miles (18 kilometers) and drop 165 feet (50 meters) in elevation.

The cave was recognized as a Ramsar site in 2003, which brought attention to its role in protecting underground water. Since then, it has been part of efforts to safeguard the wetland and the species that depend on it.

The cave is a local landmark for people in the nearby villages, who rely on the water that flows from it to irrigate their gardens and feed their animals. Visitors often see shepherds and farmers passing near the entrance, a reminder of how daily life here is tied to the underground river.

The cave entrance is in a rural area, so you will need your own vehicle and should check local conditions before setting out. Bring a torch and wear sturdy shoes, as the ground inside is uneven and the passages are dark.

This is the largest known underground cave system in Africa, and it is fed by the Tafna River beneath the Tlemcen Mountains. The cave contains high chambers and underground lakes, and the surrounding area is home to the endangered Egyptian vulture.