La cárcel de Carabanchel, Europe’s biggest and most notorious prison until its closure in 1998, was built under General Franco’s watch. Between 1940 and 1944, every wall was raised and every metal door was fitted by the same prisoners who would eventually do their time here. None dared lay a brick loosely or leave a screw untightened – this prison was a star-shaped fortress, and nobody was escaping.

Those seven little holes lead to an underground prison where over the centuries, controversial influencers of their time were incarcerated.