The present Hospital de la Santa Creu i Sant Pau (Catalan for Hospital of the Holy Cross and Saint Paul) in the Guinardó, Barcelona, Spain, is a complex built between 1901 and 1930, designed by the Catalan architect Lluís Domènech i Montaner. Together with Palau de la Música Catalana, it is a UNESCO World Heritage Site. Today it is still a fully functional hospital. There have been discussions to convert this building to a museum sometime in the future.

Although the hospital's current buildings date from the 20th century, the Hospital de Sant Pau was founded in 1401 when six small medieval hospitals merged. The hospital's former buildings near the center of Barcelona date from the 15th century, and now house an art school (Escola Massana) and Biblioteca de Catalunya (National Library of Catalonia).
Source: Wikipedia