The Castle can be visited
Museum
Muiderslot

In Muiden, Netherlands, the Muiderslot, a medieval water castle, is situated at the mouth of the Vecht River. Its strategic position once made it an important stronghold for controlling trade.
History+
The origins of the Muiderslot date back to 1280, when Count Floris V had a stone fortress built on this site. This served to collect tolls on the trade route to Utrecht. In 1296, Floris V was abducted here by a group of nobles, including Gerard van Velsen, and killed during an escape attempt. Just one year later, the castle fell to Willem van Mechelen. Between 1370 and 1386, the structure underwent extensive renovations under Duke Albert I of Bavaria, who was also Count of Holland and Zeeland.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Peter van der Wielen
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 52.3344, 5.0714