Castel Sant Angelo is one of our favorite sites in Rome, simply because of its great history and unique construction. When you're roaming around Rome, you will notice a tall cylindrical building that seems a bit grander than anything around it. This was the tallest building in Rome when it was made. The original name of this place is The Mausoleum of Hadrian as it was constructed upon the orders of Hadrian, the Roman Emperor, to serve as a mausoleum for him and his family. Later on, the building was used as a fortress at times, a castle by some popes, and even a prison once. Castel Sant Angelo is very popular with tourists due to its illustrious history, and for offering some of the best views the city has to offer. The castle and its surroundings are some of the best photo op places in Rome. You can always visit Castel Sant Angelo during the day; however, we would recommend going here before sunset and just spending a few hours here. The castle is at its most beautiful during sunset and the lighting on it at night makes it look magnificent.