With skip the line entrance tickets and your expert guide, begin in 138 AD when the Castel was originally built as a funeral monument for Emperor Hadrian. Here you can still explore the mausoleum dedicated to him. Explore the Treasury room deep inside the castle, where it is said his ashes were originally placed before the 5th century sacking of Rome.

As you make your way through the castle, visit the frescoed Papal apartments. Hear about the lives of the pope's and cardinals who resided here - such as the Borgia, and others who hid away when crisis struck.

Stand in a torture chambre in the courtyard where numerous executions were held, and see the famous Passeto Secreto - the 'secret passageway' that connects the castle directly with the Vatican which inspired Dan Brown's book Angels and Demons.

Finally, enjoy stunning views of the city from the top of the monument where Archangel Michael stands armed with a sword, guarding the city.