In the year 1115, fortifications were erected at the site by Gosewijn I, Lord of Valkenburg. This original wooden keep survived until 1122 when it was destroyed under siege by Henry V, Holy Roman Emperor. The castle was rebuilt in the following centuries but was again destroyed in a siege, this time by Jan III, Duke of Brabant. The current ruins are those of the castle rebuilt in the 14th century.
The castle was blown up during the Franco-Dutch War, in 1672, by the army of King-Stadtholder Willem III to prevent it falling into French hands.
References:The Cathedral of Saint Mary Major, often called Lisbon Cathedral or simply the Sé, is a Roman Catholic cathedral located in Lisbon, Portugal. The oldest church in the city, it is the seat of the Patriarchate of Lisbon. The cathedral has survived many earthquakes and has been modified, renovated and restored several times. It is nowadays a mix of different architectural styles.
The site where it stands was the principal mosque of Lisbon when it was an Arab settlement. The construction of the cathedral started around 1150, three years after the city was conquered from the Moors during the Second Crusade. Shortly after the victory the English knight Gilbert of Hastings was named bishop of the city of Lisbon.
One good reason to visit the Cathedral is to visit its charming cloisters located in the back. There are several tombs in the cathedral, the most notable of which is the beautifully sculpted tomb of Lopo Fernandes Pacheco and his wife.