The Museo Nacional Centro de Arte Reina Sofía in Madrid is Spain's national museum of C20 art, mainly Spanish, and is housed in a huge and spectacular C18 former hospital which closed in 1969. The museum opened in 1990 and has since been extended, most recently to a design by Jean Nouvel, but the original parts, with their long corridors and wards set round a beautiful inner courtyard are still the best. It is a wonderful place to see Guernica by Picasso.