Muiderslot

"Who doesn't love castles?! The one closest to Amsterdam is the 'Muiderslot'. The town to which the castle belongs isn't overly exciting, but there are a few nice things to do. Close to the castle are the remains of a fortress, as Muiden is another fortrified town ("vestingstad"). Much of Muiden has been built around a harbour, so you can make the most of that by hopping on a ferry to the island 'Pampus'. This man-made island as part of a defence system in the late 19th century. But getting back to the castle: this is the best reason to go to Muiden. In summer, the gardens next to it are very pretty, too, but the castle itself is good in any season."

"Muiden Castle is a castle in the Netherlands, located at the mouth of the Vecht river, some 15 kilometers southeast of Amsterdam, in Muiden, where it flows into what used to be the Zuiderzee."