The third-largest church building in the world (and the largest cathedral), Seville Cathedral is every bit as big as you think it is, possibly bigger. It also happens to be spellbindingly beautiful too, all stunning Gothic arches and 15th century magnificence. The cathedral was built on the remains of a mosque and has actually retained a couple of those features, but this is a house of Catholicism and then some, home to the longest nave in Spain and a quite incredible section of paintings depicting the experiences of Christ. The views from the top of the Giralda? You’ll just have to see for yourself. Expect plenty of queuing in the busy months, so buy your tickets ahead of time and save yourself the stress. Oh, Christopher Columbus is buried here as well, if you needed any more reasons to visit.