- First Town Wall
- The first town wall was erected following construction of the fortresslike residence on the Coudenberg hill. The decision to build the oblong circuit of walls was probably made by Duke Lambert II and construction began about 1063, with completion under Henry I n about 1100. In enclosing the Grand' Place, early churches, and the ducal palace, the wall gave Brussels the structural character of a town. The ramparts stood at an average height of 7 m (23 ft.) and were built of sandstone brought from nearby quarries. The circuit included seven gates and approximately 40 defensive towers.The wall ran about 4 km (13,120 ft.) and enclosed a space of about 80 ha (198 acres) along a course roughly extending from the place Sainte-Catherine east to the Coudenberg heights and west to the Senne River abreast of the church of Notre-Dame de Bon Secours and north to the place Saint-Géry to close at the place Sainte-Catherine. The remains of four towers have been preserved: Tour Noire, Tour Anneessens, Tour de Villers, and Tour de Pléban.
Historical Dictionary of Brussels. Paul F. State.