This huge fortress built between 1850 and 1871, a UNESCO World Heritage Site, is a perfect example of the military architecture of Central Europe. It comprises three bastions connected by moats and covers an area of over 70ha. However, from the outside, built low to the ground, the castle is almost invisible. A visit is the only way to appreciate the impressive dimensions of this stronghold. Rotating vaults, immense poles and the excellent craftsmanship of the bricklayers are just a few of its attractions. The fortress also once housed the Soviet Army, who used it as a munitions depot.