The photos are some of the perfect views from the top level of the castle. In one of the photos you can see an aqueduct running from the castle to the Vatican. That's actually a popeaduct, as its sole purpose is to house a raised passageway connecting the Vatican palace to the castle, enabling the pope to flee to the greater protection afforded by the castle during all the riots and invasions.

Since the popes spent alot of time here, the interior, which was previously focused on housing and torturing prisoners, evolved to a sort of palace, albeit with no windows and really thick walls. One practical note to visitors; the only public bathroom is on the entry level at the roof, prior to descending through the many levels of the palace to the eventual exit. So go before you start the descent, or you'll regret the very long backtrack.