Lalibela, an important pilgrimage town in the heart of north Ethiopia, is one of the most amazing places I know in Africa. The place was the capital of the Zagwe dynasty that ruled this part of Ethiopia sometime between the 10th -13th century.
At that time, a king named LALIBELA started a huge project of excavating churches in the soft tuff red rock. The result is over 10 churches, some of them monolithic, some of them semi-monolithic, and some churches are built inside caves. All churches are carved from outside and inside, each one with its own architecture!
Although carved about 800 years back, the churches are still active to-day! I find it most amazing, and being there, especially on the orthodox Christmas day (12/1), is really spiritual event.