The Île de la Cité (French pronunciation: [il də la site]) is one of two remaining natural islands in the Seine within the city of Paris (the other being the Île Saint-Louis). It is the centre of Paris and the location where the medieval city was refounded.
The western end has held a palace since Merovingian times, and its eastern end since the same period has been consecrated to religion, especially after the 10th century construction of a cathedral preceding today's Notre Dame. The land between the two was, until the 1850s, largely residential and commercial, but since has been filled by the city's Prefecture de Police, Palais de Justice, Hôtel-Dieu hospital and Tribunal de Commerce. Only the westernmost and northeastern extremities of the island remain residential today, and the latter preserves some vestiges of its 16th century canon's houses. The Mémorial des Martyrs de la Déportation, a memorial to the 200,000 people deported from Vichy France to the Nazi concentration camps during the Second World War, is located at the upriver end of the island.
Notre Dame de Paris (IPA: [nɔtʁə dam də paʁi]; French for "Our Lady of Paris"), also known as Notre Dame Cathedral or simply Notre Dame, is a historic Roman Catholic Marian cathedral on the eastern half of the Île de la Cité in the fourth arrondissement of Paris, France. Widely considered one of the finest examples of French Gothic architecture and among the largest and most well-known churches in the world, Notre Dame is the cathedral of the Catholic Archdiocese of Paris; that is, it is the church that contains the cathedra (official chair) of the Archbishop of Paris, currently André Vingt-Trois. The cathedral treasury is notable for its reliquary, which houses the purported crown of thorns, a fragment of the True Cross and one of the Holy Nails – all instruments of the Passion and a few of the most important first-class relics.