Île Saint-Louis, eleven hectares in size, is one of two natural islands in the Seine river, in Paris, France. Île Saint-Louis is connected to the rest of Paris by four bridges to both banks of the river and to the Île de la Cité by the Pont Saint-Louis.

Île de la Cité is an island in the river Seine in the center of Paris. In the 4th century, it was the site of the fortress of the area governor for the Roman Empire. In 508, Clovis I, the first King of the Franks, established his palace on the island. In the 12th century, it became an important religious center, the home of Notre-Dame cathedral, and the royal chapel of Sainte-Chapelle, as well as the city hospital, the Hôtel-Dieu. It is also the site of the city's oldest surviving bridge, the Pont Neuf.