Archaeologists excavating the large and mysterious mound at the Kasta Hill site at Amphipolis, Greece, have unearthed a broken marble door, Greece’s Culture Ministry announced today.

Made from marble brought from the island of Thasso, like most of the features uncovered so far in the underground space, the door fragments were found as archaeologists removed dirt from the second chamber.

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According to Katerina Peristeri, the excavation’s director, the discovery leaves no doubt the structure is indeed a tomb dating to the time of Alexander the Great of Macedonia.

“Based on our findings, we are absolutely sure about our dating to the last quarter of the 4th century B.C.,” Peristeri said.

She hinted their dating relies on strong yet unpublished findings.

“We give information out to provide a clear picture [of the excavation]. However, not all the material is coming out in press releases,” Peristeri said.

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Leading to the tomb’s third chamber, the marble door features a double row of dots down its center. The dots imitate nail heads, a feature common on Macedonian tomb doors.

A hinge was also discovered on the western side of the door.

“What is particularly unusual here is that the door was in two sections and hinged,” Dorothy King, a classical archaeologist not involved in the excavation, wrote in her blog.

“It was designed to open rather than merely be a ‘fake’ door designed to look like one as seen in most other Macedonian tombs,” she said.

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She noted that temples had doors that opened and closed, “but they tended to be either wood inlaid with ivory or wood covered in bronze,” King said.

Behind the two fully unearthed Caryatids (female statue) and in front of the door, Peristeri’s team also found bronze and iron nails. It’s not clear whether they belonged to the funerary carriage or something else.

As for the broken marble door, Peristeri believes it collapsed either as a result of the Bulgarian army’s bombing in 1913 or as the consequence of a severe earthquake that rumbled in Amphipolis in the 6th century A.D.

According to the archaeologists, Greece’s mystery tomb may hold more surprises.

It’s possible that a staircase or ramp exists behind the door in the third chamber, leading to a 6.5-foot-deep room.

Image: The marble door features a double row of dots meant to imitate nail heads (left); drawing showing the door design. Credit: Greek Ministry of Culture.