Sheltered by medieval walls, Avignon’s maze of narrow streets is filled with churches, museums and palaces tracing the history of this ancient, vibrant city. Visitors can capture a bird’s-eye view of the city and surrounding Rhône River valley from the top of Cathedral Hill. Avignon is known as the “City of Popes,” due to the role the city played in the Avignon conspiracy of the 14th century, when a pope abandoned Rome and fled here. Avignon’s lavish Palais des Papes (Palace of the Popes), a fortress, church and palace, was considered the center of the Christian world during the 14th century. From 1309 to 1377 seven popes resided in this impressive building, one of the world’s most fascinating examples of Gothic architecture. Another must-see is the Pont d'Avignon, a ruined 12th-century bridge that once spanned the Rhône and is immortalized in a folk song about dancing on the bridge. In all likelihood, people actually danced under the bridge on the Île de Barthelasse, once a popular recreation spot.