The statue at the top of the castle is that of an angel, after which the castle is named.
Here you can see tourists milling around the castle in Rome. The two statues at the gates of the castle are visible in the photograph. More statues line the pathway to the entrance. This is the front view. The first two statues are of Roman personages.
This is a sketch of the Roman castle or the Mausoleum of Hadrian from the canal side.
Related images: Photographs of the Colosseum at Rome, Italy or Colosseum Sketch and Silhouette or Sistine Chapel in the Vatican City in Rome Italy
Trevi Fountain (Fontana di Trevi) in Rome or for another castle from a different part of the world: Tower of London Photograph, Sketch and Silhouette