CHAMAS, St, a town of France, department of Bouches-du-Rhône, on the north bank of the lagoon De Berre, 24 miles N.W. of Marseilles. It is well built, and is divided into two parts by a hill, through which a large tunnel has been cut. It has a fine church; a large powder magazine, which supplies Toulous; and a trade in oil and olives, which are shipped from its port on the lagoon. In the vicinity is a Roman bridge of a single arch, with a triumphal arch at each extremity. Pop. 3000.