The Loire is a river in France, 1,013 km long, and with an area of 117,000 km² in its catchment area. The river rises in the Massif Central mountains in southeastern France and flows into the Atlantic Ocean near the city of Nantes via an estuary. The Loire is the longest river in France. The middle part of its course is known as the "Loire Valley" and is included in the UNESCO World Heritage List. Extremely beautiful castles are located along the river.