Along with Sagrada Família, Spain's sights to book ahead include Barcelona's Picasso Museum, La Pedrera, Casa Batlló and Park Güell; the Palacios Nazaríes at the Alhambra in Granada; and the Royal Alcazar Moorish palace, Church of the Savior and cathedral in Sevilla. Barcelona's Casa Amatller and Palace of Catalan Music, and Salvador Dalí's house in Cadaqués all require a guided tour, which also must be booked ahead. Advance tickets for the Dalí Theater-Museum in nearby Figueres are also a good idea. While it may be technically possible to buy tickets on-site, in my guidebooks I simply say you must reserve in advance. It's much smarter.
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