“A church cut into rock is an eternal sight and this, the monastery of Geghard in Armenia’s Upper Azat Valley, has several in a medieval complex. The monastery began as a small cave chapel, which Gregory declared held a sacred spring in the 4th century, and perhaps due in part to its awesome location, with looming cliffs and the Azat river gorge, became the ecclesiastical and cultural center of medieval Armenia. The name “Geghard” refers to the spear that wounded Christ, and Dan Brownites will enjoy the fact that the spear remains here,” Lonely Planet said of the monastery built in  4th–13th centuries.

Other architectural masterpieces on the list include the Sydney Opera House, Petra in Jordan, Aya Sofya in Istanbul, Lincoln Cathedral in England, Shah Mosque in Iran and others.