There was originally a Roman castellum (Castellum Laurum) in Woerden, as part of the limes of the Roman Empire and thus part of the defense lines of the northern border of the Roman Empire. The first castellum was built in the 40s AD, and was destroyed in 69 AD during the Batavian rebellion. In 70 AD the castellum was rebuilt, and the Romans remained until 402 AD, with an interruption lasting from about 275-300 AD. The Castellum was located at the present site of the medieval Petruschurch and surrounding church yard. During construction work on a new underground parking facility in the city center of Woerden, the remains of numerous old Roman buildings and a Roman cargo ship were found.
The current castle was built in around 1160 by bishop Godfrey van Rhenen. Due to its strategic location on the border between the County of Holland and the Bishopric of Utrecht, various wars have been fought in and around Woerden. In 1410 John III, Duke of Bavaria-Straubing reconstructed the castle.
Until the 19th century the castle was used as a prison. There's even a pit prison in the northwest tower, which was used for unruly prisoners. In the 20th century the castle was part of military barracks and used for storage of all kinds of goods but poorly maintained. This caused severe decay. Today it is restored as a restaurant.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.