Watchtower of Venturada Monument · Venturada, Sierra Norte, Madrid An Andalusi circular watchtower raised between the 9th and 10th centuries within the Middle March, which communicated by smoke signals with the watchtowers of El Berrueco, Torrelaguna and El Vellón to control the way up into the mountains. Photo: Anita1000 (CC BY-SA 3.0) What to see and do in Venturada