Montjuïc Castle (Spain)
As part of the city walls, this castle was an old military fortress. It was renovated in the 17th century and until 1960, it served as a military prison. Allegedly, executions were regularly happening here during the civil war from 1936 to 1939. After that, it was turned into a military museum which closed in 2009.
Nowadays you can take a tour of the castle and explore permanent and temporary exhibitions devoted to the history of both the castle and the hill. One part of the exhibition is dedicated to the trials and executions that happened here while the castle served as a prison. The place also holds educational exhibitions and cultural events. Go out to the terrace to enjoy 360º views of the city.
It takes about 25 minutes to walk to the castle from the top of the funicular, but you can also take a cable car which ends right in front of the castle. The castle can also be reached by car or by bus that goes around Montjuïc Hill.