Hadrian's Tomb (Castel Sant'Angelo), Rome, Italy

It was originally built by the emperor Hadrian as a mausoleum for his family. The original building was a cylindrical shape with a garden on top and golden quadriga (4-horse charriot. The ashes of Hadrian, his wife Sabina, and his first adopted son, Lucius aelius were placed in the tomb. The ashes of his decendents up to Caracalla, who died in 217, were also placed here. Hadrian's ashes were placed here a year after his death in Baiae in 138.

In 401 the mausoleum was converted into a defensive structure. Flavius Augustus Honorius made it part of the Aurelian Walls. When Alaric's Visigoths sacked Rome in 410 the ashes of the family were scattered. In 537 the bronze ornaments and stone statues were thrown over the walls onto the attacking Goths

In later times the popes converted the mausoleum into a castle. Pope Nicholas III connected it to St Peter's Basilica by a fortified corridor. The then named Sant'Angelo was also used by the popes as a prison. Giordano Bruno spent 6 years imprisoned in it.

According to legend, an angel appeared on top of the mausoleum and sheathed his sword as a sign that the plague of 590 had ended. The bronze statue of Saint Michael sheathing his sword, completed in 1753,  was placed on top of the structure to commemorate this legendry event, but it replaced the original marble statue from 1536 that is now in the interior.

The castle was decommissioned in 1901 and is now the Museo Nazionale di Castel Sant'Angelo.