Calle Marqués del Real Tesoro, 10, 11001 Cádiz, Spain
Torre TaviraAs a harbor city of global stature, Cádiz always needed to keep an eye on the sea and every townhouse of importance had its own watchtower. Of the original 160, 129 remain, and the best known of these is Torre Tavira. It's a popular attraction, thanks to its panoramic camera obscura on the top floor. Light passing through a pin-sized hole projects a wide-screen view of the Cádiz skyline.