This document provides information about the ancient Roman city of Corseul in Brittany, France. It describes Corseul as the capital city of the Coriosolis tribe, founded around 50 BC and originally called Fanum Martis. Fanum Martis had approximately 10,000 inhabitants and covered 11,000 square meters. Like other Roman cities, it was built according to a grid plan with two main streets (cardo and decumanus) intersecting at the forum and other important buildings. The document discusses the layout of a wealthy Roman home (domus), the nearby Temple of Mars (one of the largest Roman temples in Brittany), and the sacred cella tower at the center of the temple precinct where