"This massive former hospital complex dominates nine blocks of the Eixample district, and it's one of the finest examples of early-20th-century modernista (Catalan art nouveau) architecture. Lluís Domènech i Montaner designed the grand main hall and multiple pavilions in a hybrid Gothic-Moorish style: The redbrick buildings feature turrets, spires, and arches, and their facades are decorated with ornate sculptural elements, ceramics, and mosaics. Administration Pavilion is the standout, with its soaring marble columns, vaulted ceilings lined in colorful tiles, and stained-glass windows and skylights throughout. Guided tours are offered in English but you can also easily navigate the grounds on your own."