Tumulus of Achilles and sacrifice of Polyxena. Kızöldün Tumulus is the oldest known tumulus of Hellespontine Phrygia. It was found in the Granicus River valley, near Biga in the Province of Çanakkale in 1994. The discovery was the result of the rescue operations carried out after the authorities had been notified about illegal digs in the area. Within the tumulus, the archaeologists found two marble sarcophagi: one representing the sacrifice of Polyxena, dating to around 500–490 BCE, and another containing the body of a 10-year-old girl, buried 40 or 50 years later.

Polyxena Sarcophagus is a remarkable object as it is one of the earliest stone sarcophagi with figural scenes ever to have been found in Asia Minor. It represents the early example of the Proconnesian marble workshops. It has impressive dimensions of 3.32 meters in length, 1.60 meters in width, and 1.78 meters in height. A whole in the cover of the sarcophagus indicates that it had been robbed in antiquity. Moreover, fragments of a wheeled cart that transported the corpse to the tumulus were discovered beneath the terracotta tiles that surrounded the sarcophagus. Although the figures of the reliefs depict mainly women, the person buried was a 40-year-old man. The reliefs on the sarcophagus show a funerary celebration on three sides, and on the back what is believed to be the sacrifice of Polyxena by Neuptolemos in front of the tomb of his father Achilles. Although not mentioned by Homer, Polyxena was a well-known figure of Greek mythology. She was the youngest daughter of King Priam of Troy and his wife, Hecuba. An oracle prophesied that Troy would not be defeated if Polyxena's brother, Prince Troilus, reached the age of twenty. The siblings were ambushed when they were attempting to fetch water from a fountain, and Troilus was killed by Achilles, who soon became interested in Polyxena. He seemed to trust Polyxena, and he told her of his only vulnerability: his heel.

Polyxena revealed this secret to her brothers, Paris and Deiphobus, who ambushed Achilles and shot him in the heel with an arrow. At the end of the Trojan War, Achilles' ghost came back to the Greeks to demand the human sacrifice of Polyxena to appease the wind needed to set sail back to Greece. She was to be killed at the foot of Achilles' grave. Polyxena was eager to die as a sacrifice to Achilles rather than live as a slave. She refused to beg for mercy and died bravely as the son of Achilles, Neoptolemus, slit her throat."