Torre del Oro in Seville

You're standing at the Torre del Oro, the Tower of Gold, on the Guadalquivir river in Seville. Take a good look at its shape. The tower has twelve sides and is made up of three sections, one on top of the other. Right at the top sits a round turret. That was only added in 1760, and it was the work of the military engineer Sebastian Van der Borcht, who was also the architect of Seville's Royal Tobacco Factory.