1. Buda Castle
Buda Castle sits on a hill overlooking the Danube, a massive palace complex that has dominated the Budapest skyline for centuries. The first royal palace here dates back to the 1300s, though what you see today is mostly the result of rebuilding after the Ottoman occupation and later wars. The current structure blends Gothic foundations with Baroque and Neobaroque additions from the 18th and 19th centuries. Inside, the castle houses the Hungarian National Gallery, the Budapest History Museum, and the National Széchényi Library. The courtyards are open to wander through, and the views across the river to Pest are some of the best in the city. The castle district around it, with its cobblestone streets and medieval houses, is a UNESCO World Heritage site.