A closer look

If you can't conquer Jerusalem, you carve a new one straight down into the bedrock. In the 12th century, Ethiopian King Lalibela decided to bypass the Islamic forces controlling the Holy Land by commanding the construction of 11 monolithic churches. Instead of building up, thousands of workers chiseled perfectly straight downward into volcanic tuff, freeing massive, intricate cathedrals from the earth without using a single nail, brick, or drop of mortar.