Virtually an open-air museum of Mudéjar architecture, Teruel is visually stunning. In 1986, UNESCO designated the cathedral and three other churches in town as the Mudéjar Architecture World Heritage Site. The sheer beauty of the town makes it worth a trip if you’re anywhere in the vicinity. That being said, Teruel was once even more architecturally distinguished than you will find it today. It was the site of the bloodiest battle of the Spanish Civil War. As the city changed hands several times between December 1937 and February 1938 in the worst winter cold recorded in Spain up to that time, more than 140,000 soldiers died and many of the city’s medieval structures were destroyed in the bombardment.