Hadrian's Tomb, Then Fortress, Residence and Prison, Plus the Escape Route

Two Roman sites on one skip-the-line ticket, and they are joined to each other.

The Passetto di Borgo is the old passage running from Vatican City to Castel Sant'Angelo. It was not built for sightseeing: when things went badly for a pope, this was the way out.

At the far end is Castel Sant'Angelo, which has been four different buildings in its life. It went up as the mausoleum of the emperor Hadrian. It became a fortress. It became a papal residence. It served as a prison. Each use left something behind, and what is inside now is the accumulation of all four, along with the view over Rome from the top.

One thing to weigh before booking: this ticket cannot be cancelled or refunded.