Steinsburg is the colloquial name for the remains of a Celtic oppidum on the Kleiner Gleichberg in the German state of South Thuringia.
In clearing large parts of the stone field for roadbuilding (from 1838), metal objects and other artefacts were discovered that were later recognised as of Celtic origin.
The increasing amount of basalt quarrying from 1858 destroyed parts of the hillfort, especially the easily accessible lower wall rings, and brought a huge quantity of archaeological finds to the surface, of which mainly the metal objects have survived in various collections.
In 1929 the Steinsburg Museum was built on the saddle between the Großer and Kleiner Gleichberg and this is where the majority of finds are still on display today.
In addition, the older finds include very few items of pottery, because pieces of old ceramic vessels were not looked after in the 19th century.