While Sagrada Familia deservedly draws massive crowds, those seeking a quieter modernist experience should discover Hospital de Sant Pau. This UNESCO World Heritage site by Lluís Domènech i Montaner offers equally stunning architecture without the tourist circus atmosphere.

Entry costs €15 versus €26 for Sagrada Familia, and you can actually walk around in peace instead of being herded through gift shop queues. The underground tunnels connecting pavilions are architectural jewels, and the rooftop views toward Sagrada Familia beat anything you'll see from inside that overpriced monument.

Metro L5 to Sant Pau-Dos de Maig, exit toward Carrer de Sant Antoni Maria Claret, 5-minute walk to Carrer de Sant Quintí, 89. Open 10am-6:30pm daily (closed Mondays). Guided tours in English at 11am daily for €3 extra - actually worth it for the medical history context.

The ceramic details catch golden hour light perfectly around 6pm, and you'll have the place mostly to yourself. Perfect complement to Sagrada Familia if you want to understand Barcelona's modernist movement beyond just Gaudí.