"This mirador, or viewpoint, is worth the climb for its unparalleled 360-degree views of the entire city, the Mediterranean Sea, and the rolling green hills of Collserola. Located some 900 feet above sea level, the hilltop was considered a strategic spot for defending Barcelona from bombings during the Spanish Civil War; anti-aircraft batteries and gunner bunkers were built here for this purpose. After the war, there was a desperate lack of housing, and the abandoned military structures were incorporated into a shantytown. Remarkably, people lived here until 1990, when the city took it over and turned it into a heritage site, complete with illuminating photographs and signage detailing the history of this unique place."