It is in the heart of Saint-Géry/Sint-Goriks Island, formed by the Senne river, and on which a first keep was built around 979, that the origin of Brussels is located. Today, the neighbourhood around the /, a former covered market, is one of the trendiest districts of the capital. In this Central Quarter (, ), there are some vestiges of the 13th-century first walls of Brussels, which surrounded the area between the first port on the Senne, the old Romanesque church (later replaced by the Brabantine Gothic Cathedral of St. Michael and St. Gudula), and the former ducal palace of Coudenberg in today's Royal Quarter. In the centre of this triangle are the Grand Place (Brussels' main square); the Îlot Sacré district, which takes its name from its resistance to demolition projects, itself crossed by the Royal Saint-Hubert Galleries; the / district, which welcomed the pilgrims on their way to Santiago de Compostela; as well as the former Brussels Stock Exchange building, built on the site of a former convent, whose remains have been uncovered.