The Spandau Citadel, a fortress dating back to the Renaissance period, stands as a testament to Berlin's rich history. Built between 1559 and 1594, it was designed to protect the town of Spandau and now serves as a cultural hub, offering open-air concerts and housing a history museum within its walls. Notably, the citadel also shelters a unique bat colony in its cellar, adding an ecological aspect to its historical significance.