Lalibela, Ethiopia

Of all the incredible monuments in Ethiopia, the rock-hewn churches of Lalibela are by far the most impressive. Starting in the 12th century A.D., Ethiopian rulers dug a series of churches out of the solid bedrock. This architecture-in-reverse creates a bizarre and otherworldly scene. As you walk along the exposed rock, you come across giant holes in the stone filled with churches. Narrow steps take you down into the pits, where you'll find some welcome shade from the powerful African sun. Enter the churches and you'll come upon pilgrims and priests studying the Kebra Nagast and Bible by the dim light steaming in through stone grills high in the walls. Further in the gloom, you'll spot the gleam of elaborate gold and silver crosses as incense wafts through the air.