Biete Maryam — the House of Mary — is one of the most ornate of the Lalibela churches and one of the most important sites of Marian devotion in Ethiopia. It is carved from the same volcanic tufa as the other churches but distinguished by remarkably detailed exterior carvings: blind windows with intricate geometric patterns, a carved Axumite frieze, and windows in the shape of the Ethiopian cross.
The interior walls are covered in frescoes depicting biblical scenes and Ethiopian saints. These are not museum pieces but living devotional images maintained by the church. Biete Maryam sits at the heart of the northern group of churches and is connected to its neighbours through underground tunnels. It has a small bathing pool cut into the rock floor which pilgrims use for ritual bathing; on feast days it fills with worshippers. This is probably the single busiest church in the complex after Biete Giorgis, and is particularly crowded at Christmas (Genna, around 7 January) and Easter (Fasika).