Seville’s immense cathedral, officially the biggest in the world, is awe-inspiring in its scale and sheer majesty. It stands on the site of the great 12th-century Almohad mosque, with the mosque’s minaret (the Giralda) still towering beside it. After Seville fell to the Christians in 1248 the mosque was used as a church until 1401. Then, in view of its decaying state, the church authorities decided to knock it down and start again. ‘Let us create such a building that future generations will take us for lunatics’, they decided (or so legend has it). The result is a cathedral measuring 126m long and 83m wide.