Castel Sant'Angelo in Rome was originally built in 123 AD as a tomb for the emperor Hadrian and his family. Over the centuries, it served as a residence for several popes and a place of imprisonment. It underwent many transformations from a funerary monument to a fortified outpost to a Renaissance residence, while also functioning as a prison and museum at different times. The castle has accompanied the fortunes and history of Rome for almost two thousand years, embodying important spaces and events in the Eternal City where past and present are linked.