The Celtic ring fort

This massive Celtic fort, one of the largest found by archaeologists, was built by the Treveri tribe. Finds suggest that due to the size of the complex, it not only represented an imposing defensive structure but was also possibly a settlement and the seat of a local chieftain of the Treveri. The fort is located on the top of the Dollberg, a hill near Otzenhausen, at about 695 m above sea level. The only visible remains are two circular earth ramparts covered with stones. The earliest fortification dates back to the 5th or 4th century BCE, but the real heyday and use of the building lie between the 2nd and 1st centuries BCE. 

The site is triangular in shape with rounded ends. The entire defensive circle forms a ring of protection called a ‘Ringwall’, a circular embankment used as a defence in military fortifications, hill fortresses or Germanic shelters. 

The common point of these works was its circular-shaped barrier, which was the first defensive obstacle. It could be built in different ways: as a simple earthen causeway, an earth and timber causeway, or a wall. Usually, fortified ramparts had a moat or trench on the outside; sometimes, it was further defended with a palisade. Inside, these circular structures housed buildings such as stables, saloons and other secondary structures.

Here, on the southern side, another similar rampart is built about 40 metres in front of the main one. Since the entrance to the main rampart is on the western side, no significant purpose has yet been determined for the outer one. From west to east, the fort extends 460 metres, and from north to south, 647 metres. The total length of the ramparts is about 2,500 metres and contains 240,000 cubic metres of stone, a true feat for the time. Thousands of beams were attached to the ramparts, which probably had a vertical stone wall to the outside. Despite the portent of this military architectural work, there are few sources about its use. In the writings of Julius Caesar’s Commentarii De Bello Gallico, we have no precise information about the Celtic fort of Otzenhausen nor about Roman legions attacking it. Looking at this defensive structure, however, we can imagine the approach of two different cultures, that of the Romans, strongly characterised by organisation and expansionist politics, and that of the tribes of Germania, represented by societies closely linked by blood ties and in close contact with nature. This fort, whether it was actually the scene of battle or not, certainly saw the unflappable invasion of Roman legionaries in this area, who subjugated it and turned the entire region into a Roman province.