The vast Coudenberg Palace, once the pride of the princes and governors of these lands, disappeared in the 18th century. After the fire of 1731, it was finally demolished more than forty years later to make way for the Royal Quarter as we know it today. More than 25 years of archaeological excavations brought to light remains of the palace and its surroundings. Visitors can still discover the cellars of the main building of the medieval castle of the Dukes of Brabant (12th-14th centuries), the foundations and substructures of the palace chapel built under Emperor Charles V, the Hoogstraeten mansion with its remarkable Gothic gallery, and the lower levels of the kitchens and the Aula Magna. The Rue Isabelle has also been exceptionally preserved. Once linking the Coudenberg to the collegiate church of Saint Gudula, it now almost allows visitors to walk underground from Place Royale to the Centre for Fine Arts. A unique descent into a vanished Brussels. (Listed since 04/07/1984 and 31/01/1992)