Ljubljana Castle (Ljubljanski Grad) dominates the Old Town from its position atop a wooded hill. It's visible from pretty much everywhere in Ljubljana. Although there have been fortifications on this vantage point, the current fort dates largely from a 16th-century reconstruction following the earthquake of 1511. The castle was a royal residence in the 17th and 18th centuries and a prison and barracks in the 19th and first half of the 20th centuries. The castle's main highlight is the 19th-century Pentagonal Tower.