The Kazematten, or, Casemates, can be found in Waldeck park in Maastricht. They are fine examples of the impressive fortifications that the city created between 1575 and 1925. They were used to stage surprise attacks on the enemy during times of siege. The two Casemates in Waldeck Park are the only ones which have survived. Guided tours will take you through a small section of the passeges, which cover a 10 KM area. It is believed that d’Artagnan, known as the 4th Musketeer, was killed in one of these passages in 1673.