Tomb of Seuthes III, Thracian royal tomb near Shipka, Bulgaria

The Tomb of Seuthes III lies beneath the 23-metre-high, 130-metre-wide Golyama Kosmatka mound south of Shipka. A wide alley leads to a façade of large rough-cut stone blocks; inside, a 13-metre corridor opens into three rooms. The first is rectangular with a corbelled vault, the second circular with a 4.50-metre dome, and the third a single granite block of about 60 tonnes hollowed into a sarcophagus with a modelled stone bed.

The mound began as a monumental temple in the second half of the 5th century BC. Around 300 BC Seuthes III, king of the Odrysians from c. 331 to c. 300 BC and founder of Seuthopolis, was buried in the third chamber. After the funeral the first two rooms were walled up and the corridor burned and filled with stones and earth. Excavated by Georgi Kitov in September–October 2004, the tomb opened to visitors in June 2016.

The name Seuthes III appears in the genitive form ΣΕΥΘΟΥ on the bronze helmet and on two silver vessels from the tomb, marking the owner. The mound stands about 10 km from Seuthopolis, the city Seuthes III founded. A gilded silver shell-shaped pyxis, 16 cm long, may have belonged to his wife Berenike, named in the Seuthopolis inscription.

The tomb lies 1 km south of Shipka and is open to visitors, reached by a wide alley leading to the façade and entrance. Inside, a 13 m corridor leads to the three chambers; the mound's slope has seen landslide activity, so expect uneven ground. The site reopened in June 2016 after restoration work.

The marble door to the circular chamber was deliberately broken after the burial; its fragments, with other stones, sealed the first two rooms, and the 13 m corridor was burned and filled with earth. A bronze head of a bearded man, found 7 m in front of the façade, is taken as Seuthes III; analysis of the casting clay places the workshop near Kazanlak.