The Muga is a river in Catalonia, Spain, that rises in the mountains of the eastern Pyrenees. It enters the Mediterranean Sea at the Gulf of Roses.
The river is 58 kilometres long. Its source is below the summit of Mont Negre, elevation 1,425 metres, which is in the French commune of Serralongue. The river passes through the village of Pont de Molins and passes through the Boadella Reservoir, where the river is dammed.
