Den Helder is a small city in the north of the Netherlands, sandwiched between the North Sea and the IJsselmeer (a large lake). It's a popular tourist destination for its beaches, sailing and cycling routes. The city is also home to the Dutch navy and is home to a number of naval museums, including the Netherlands Maritime Museum. Den Helder is a convenient base for exploring the rest of the Netherlands, with Amsterdam and Rotterdam both just a couple of hours away by train.