Lluís Domènech i Montaner built hospitals the way other people build palaces. The Hospital de Sant Pau, which stands about a kilometre from the Sagrada Família along the broad Avinguda de Gaudí, is a campus of brick pavilions covered in coloured tiles, domes and mosaics, set in gardens, and linked by underground tunnels so that patients could be moved without going out into the weather. It was paid for by a banker's bequest, begun in 1902 and finished, with his son Pere taking over, in 1930, and it continued as a working hospital for decades before the patients moved to a new building and the old one became a museum and cultural centre. Together with the Palau de la Música Catalana, it was inscribed on the UNESCO list in 1997.
The idea behind the design was that beauty heals, or at least helps, and so the wards are lined with tile, and the pavilions face the sun and the sea breezes. You can walk around the grounds, go into the Administration building with its stained glass and mosaic ceilings, and descend into the tunnels. It is one of the best things to see in Barcelona, and generally less crowded than the Sagrada Família.
Barcelona is a city of motorcycles, and a rider will fit in easily, with designated motorbike parking along many streets. Traffic is dense, though, and you should plan to arrive outside rush hour. The city has a low-emission zone, so check its rules for your bike before you go, and do not leave luggage on the machine, because bag theft is a real problem. Fuel is available at stations around the ring roads.
After a visit, the café terraces on the Avinguda de Gaudí are a pleasant place to sit, and the walk to the Sagrada Família takes a quarter of an hour. The Palau de la Música Catalana, where this stop is marked, lies in the old quarter near the Via Laietana, a short Metro ride or a pleasant walk away, and Domènech i Montaner's concert hall, with its inverted skylight of stained glass and its ceramic flowers, is a fitting partner to the hospital. Together they make a good day, and the UNESCO listing treats them as a pair.