Fort Markenbinnen is a historic military fort located in the Dutch municipality of Alkmaar. It was built between 1880 and 1920 as part of the Stelling van Amsterdam, a defensive line around Amsterdam. The fort was strategically constructed on an artificial island, surrounded by a moat. It served to defend against enemy attacks and was equipped with cannons and other weapons. Despite its military significance, the fort was never used in combat. Today, Fort Markenbinnen is a museum that showcases the history of Dutch military architecture and the role of the Stelling van Amsterdam during the two World Wars. Visitors can explore the original fortifications and exhibitions about the life of soldiers during this period.