It’s a good thing Spandau Citadel is open only during daylight hours, when the 10,000 bats that make the fortress their winter home are asleep. If you want to learn more about them, visit the Bat Showroom while you are there. The citadel and surrounding moat comprise one of the best preserved Renaissance fortresses in Europe. Start your visit in the museum located in the Commander’s House. A climb to the top of the Julius Tower (30 meters) offers a great view of the surrounding landscape. For some great beer, head back to the Commander’s House and a stop at the Citadel Tavern, where rustic meals are served in vaulted rooms and the beer garden.