Spain's sightseeing is anchored by a concentration of Western art that has no parallel outside Paris and London — three world-class museums within a 10-minute walk of each other. The Sagrada Família, the Gothic Quarter, the Picasso Museum, and the Miró Foundation form a separate argument about Catalan identity and modernism. The Alhambra in Granada is the most visited monument in Spain and among the most sophisticated Islamic architecture in existence. Seville's Alcázar and Cathedral, Toledo's medieval layers, and the Camino de Santiago pilgrimage route extend the sightseeing geography across the full breadth of the country. Tours by locals add the missing layer. Take it all in.