The 19th century was something of a golden period for Spanish paintings, and that period is the focus of the Carmen Thyssen Museum. Established in 2011, the museum is actually based on the collection of Carmen Cervera, the Barcelona-born socialite, art dealer and philanthropist best known for a 2016 tax scandal. Still, some fantastic art in here, and the 16th century building in which it is located is a hidden gem all on its own.