Aigies-Mortes (Lat. Aqua Mortuae, dead waters), a town of France, department of Gard, 3 m. from the Mediterranean and 20 m. S. S. W. of Nimes; pop. in 1866, 3,932. It owes its name to the malarious marshes which surround it, and over which it is approached by a raised causeway. In the middle ages it had a commodious port and ship canal, where Louis XII. embarked his army for the crusades in 1248 and 1270; but they have long been filled up with sand. Several fruitless attempts have been made to restore them, the last by Napoleon I. The walls and towers then built around the town are the best preserved of any in France. In the vicinity are the immense salines of Peccais, and their products, as well as fresh and salted fish, are shipped through canals to the coast and interior.