Even on a tight schedule, Prague Castle earns the hours.
Allow 3–5 hours.
Less a single castle than a walled town of palaces, churches and gardens; the scale and the views back over the city are the payoff. The catch: the 'free to enter the grounds' line is misleading — the buildings worth seeing need a paid circuit ticket, the security line can swallow 30+ minutes in season, and it's huge enough to exhaust you. Half a day minimum if you want more than a walk-through.
Per Guinness World Records the largest coherent castle complex in the world at ~70,000 m²; founded around 880 by Prince Bořivoj and a UNESCO World Heritage site. · en.wikipedia.org
Open daily 06:00–22:00 (grounds); Circuit A adult ~450 CZK and Circuit B ~350 CZK cover the Old Royal Palace, St George's Basilica, Golden Lane and St Vitus interior. · hrad.cz