Torre de los Perdigones, Seville

Torre de los Perdigones is the surviving tower of a former factory known for making lead shot, and it belongs to the old San Francisco de Paula works. Its tall, spare form preserves an industrial story: molten lead was poured through graded sieves, then gravity and moving air shaped the falling droplets into pellets. That production happened inside this tower, while the factory also made ammunition and zinc sheets.

In 2007, the tower opened as a camera obscura, turning its height into the main attraction. At about 45 metres, its optical system projects a live view onto a screen, so the image moves as the city outside changes. The device uses a mirror and lenses housed in a tube above the screen. The restored industrial tower therefore works as both a surviving factory structure and a curious viewing instrument.