Things to Do on Ile de la Cité, Paris | World In Paris
2. Visit Notre Dame Cathedral (from the outside) Notre Dame Cathedral (Our Lady of Paris) is a jewel of Gothic architecture. The cathedral is the most important monument of Medieval Paris and, without a doubt, the most important attraction on the Île de la Cité.. The construction of the cathedral began in the 12th century and was finally completed in the 14th century.