The Tomb of Seuthes III is located near Kazanlak, Bulgaria. Seuthes III was the King of the Odrysian Kingdom of Thrace from c. 331 to c. 300 BC and founder of the nearby Thracian city of Seuthopolis.
It is one of the most elaborate tombs in the Valley of the Thracian Rulers.
Wikipedia https://en.wikipedia.org/wiki/Tomb_of_Seuthes_III
Address Bulgaria
Coordinates 42°42'0.24" N 25°20'0.39" E
