In the 17C and 18C, the traders of Cadiz had more than 160 towers built to watch the arrivals of their boats but also as symbols of wealth and prestige. The location of this tower, in the upper part of the town, made it, in 1778, the official watchtower using a complex system of pavilions. In 1995 the first camera oscura in Spain was set up here and by an ingenious layout of mirrors and lenses, it shows views of the town