The Citadel in Berlin is a fortress constructed in 1559. This Renaissance military structure was built to protect the town of Spandau, which is now part of the capital city. For its age, the Citadel is well-preserved and is now open to the public. There are several small museums inside, which we explored, looking at old cannons, rifles, military uniforms and older cars. And my favorite part of the visit was climbing up to the tower, where a nice view could be found.