The churches of Lalibela were not constructed — they were excavated. The top surface of the roofs are at ground level. Local legend insists these were built overnight by angels. The true history is still a matter of debate; the 13th Century being the most popular date for their excavation. However, some historians suggest that there are indications that they go back as far as the 7th Century. Each church was excavated by first carving out a wide trench on all four sides of the rock, then painstakingly chiselling out the interior. The largest church is 40 feet high.