M'Zab Valley, also known as the M'Zab Gorges, is a UNESCO World Heritage Site located in the northern Sahara Desert of Algeria. The valley is home to a series of five fortified cities or ksour, founded in the 11th century by the Ibadi sect of Islam, a branch of the Kharijite movement.

The ksour are known for their unique architecture, which blends together elements of Berber, Arab, and Islamic styles. Each ksar is surrounded by high walls that enclose houses, mosques, and communal buildings. The walls were built with a local mud brick called tabia, which is mixed with straw and water and then left to dry in the sun. The buildings inside the ksour are also made of tabia and feature characteristic vaulted roofs made of palm wood.

The five ksour are Ghardaïa, Beni Isguen, Melika, Bounoura, and El-Atteuf. Ghardaïa is the largest and most famous of the ksour, and is home to the Great Mosque, which is the oldest mosque in the valley. The mosque is known for its beautiful architecture, including its minaret and ornate entrance gate.

M'Zab Valley is a unique and well-preserved example of traditional Islamic urban planning and architecture in the Sahara. It has been recognized as a UNESCO World Heritage Site since 1982 and attracts visitors from around the world who come to admire its unique beauty and cultural significance.