From Wikipedia:
The Glauberg is a Celtic oppidum in Hesse, Germany, consisting of a fortified settlement and several burial mounds, "a princely seat of the late Hallstatt and early La Tène periods."Archaeological discoveries in the 1990s place the site among the most important early Celtic centres in Europe. It provides unprecedented evidence on Celtic burial, sculpture and monumental architecture.Much international attention was attracted especially by the discovery of an extremely rare find, a life-sized sandstone statue or stele, dating from the 5th century BC, which was found just outside the larger tumulus. The stele, fully preserved except for its feet, depicts an armed male warrior. It is made from a type of sandstone available within a few kilometres of Glauberg. Much detail is clearly visible: his trousers, composite armour tunic, wooden shield and a typical La Tène sword hanging from his right side. The moustachioed man wears a torc with three pendants, remarkably similar to the one from the chamber in mound 1, several rings on both arms and one on the right hand. On his head, he wears a hood-like headdress crowned by two protrusions, resembling the shape of a mistletoe leaf. Such headdresses are also known from a handful of contemporary sculptures. As mistletoe is believed to have held a magical or religious significance to the Celts, it could indicate that the warrior depicted also played the role of a priest.
During an exploratory overflight in 1988, local antiquarians recognised the traces of a large tumulus in a field 300 m south of the oppidum. Between 1994 and 1997, the State Archaeological Service of Hesse excavated it. The mound originally had a diameter of nearly 50 m and a height of 6 m. It was surrounded by a circular ditch 10 m wide. At the time, it must have been a visually extremely striking monument.
Museum "Keltenwelt am Glauberg" (German)