The Cathedral of León — known as the Pulchra Leonina, the "Beautiful Leonine" — is one of the finest Gothic buildings in Spain and arguably the most remarkable for its windows. The walls are almost entirely replaced by stained glass: over 1,800 square metres of it, dating from the 13th to the 20th century. On a bright day the interior is flooded with amber and blue light in a way that no other Spanish cathedral quite matches.
The structural boldness that made this possible also created problems. The stone piers carry so much of the load that the walls between them are paper-thin, and the cathedral suffered serious structural crises in the 19th century. Major restoration work in the 1800s and again in the 20th century stabilised the building. You can still see Roman hypocaust channels under the floor — the cathedral was built on the site of the Roman baths.
Entry includes the museum, which has a collection of medieval sculpture, altarpieces, and illuminated manuscripts.