Christy Kenneally explores the art and architecture of Christianity and visits some of the earliest outposts of Christianity. He begins his journey on Ireland's Island of Inishmurray, where Celtic monks took sanctuary in beehive-shaped stone huts built to survive both the extreme climate and Viking attacks. Some of the other spectacular locations he visits include the monolithic rock-hewn cave churches of Lalibela in Ethiopia, Santa Sophia (Hagia Sophia in Greek) in Istanbul, and the spectacular Sagrada Familia Cathedral in Barcelona.