The Beni Add Caves are a natural karst cave system in Tlemcen National Park, in the municipality of Aïn Fezza, about 10 km east of the city of Tlemcen in north-western Algeria. The visitable section runs for some 700 meters at a depth of 57 meters below the mountainside, and keeps a steady temperature of around 13 °C all year round. The cave is estimated to be about 65,000 years old.

Inside, limestone and calcite formations fill a chain of halls. The best known is the Hall of Swords, named after its hanging stalactites, which look like Arab sabres. Other formations are said to resemble the Statue of Liberty or a falcon, and in one of the halls a white, marble-like wall gives off musical notes when tapped with a wooden stick. Pigeons nest in the cave.

Local tradition claims the network stretches for about 150 km, all the way into Morocco. During the Algerian War of Independence the caves sheltered independence fighters, and the French army sealed one passage with around 60 m³ of reinforced concrete to stop weapons being moved across the border. Closed during the Black Decade of the 1990s, the caves reopened to visitors in July 2006.