In front of the terrace houses, directly across the street from the Temple of Hadrian, stands a monumental tomb called the Octagon. Archaeologists discovered the tomb in 1926.
In it were the skeletal remains of an 18- to 20-year-old woman. It was indeed the custom to erect statues of influential citizens in the city center, but very few were allowed to build their tombs here. This young woman must thus have been from a wealthy and important family.
Recently, an interesting hypothesis has been presented: the woman could be Arsinoe IV, a princess of the Egyptian royal family. Her older sister, Cleopatra VII, was unpopular with her constituency, so Arsinoe was able to muster some support for her claim to the throne.
She either fled to Ephesus, or was sent into exile by Cleopatra. She sought sanctuary in the Ephesian temple of Artemis. Like all sanctuaries, it offered immunity to fugitives seeking protection. Despite this, the princess died in Ephesus; she may even have been murdered.
Since there is no tradition about a similar noble woman from this period of time, the hypothesis may well be correct.
It remains unknown who built the structure. Perhaps her sister erected the tomb to whitewash the murder of Arsinoe, or perhaps Arsinoe"s friends had it built.
Either hypothesis could explain the peculiarity of the architecture.
The octagonal monumental tomb rises from a square foundation. Eight column with Ionian capitals surround the structure. The roof was pyramidal. The sarcophagus is in the grave chamber.