Admire Gaudí’s masterpiece from outside or enter with prebooked tickets; interiors open roughly 9:00–18:00 but check exact hours and book ahead to save time.
Take the R5 train from Plaça Espanya and the cable/funicular up for dramatic cliff scenery and monastery visits — services typically run from early morning to early evening; check times before you go.
Take a daytime or overnight budget bus (or a flight from nearby Bilbao if you prefer) — buses typically take ~8–9 hours, so plan arrival time accordingly and check schedules.
Take the RER to Versailles (train ~EUR7–10 roundtrip) and decide whether to tour the palace (entry extra, ~EUR20) or enjoy the gardens free on certain days; check opening times and free-access days before going.
Take the metro or RER to your onward transport (allow extra time for transfers and security); metro tickets vary but allow ~30–60 minutes travel time depending on location.