We walked north along the river to perhaps my favorite building in Rome, the Castel Sant'Angelo. The circular tower was built by Emperor Hadrian in 138 AD to be his tomb. He purposely chose this place on the "wrong" side of the Tiber so it could be a peaceful, permanent memorial to his greatness. The beautiful bridge crossing the Tiber to allow people to come and pay homage was also built around that time. When Hadrian died, he was of course buried in the building, but due to its unparalleled defensive position, it was immediately turned into Rome's chief fort, prison and torture center. Public executions took place almost every day with the dead left swinging from the bridge, while the many levels of subterranean dungeons hosted most of the torturing activity.