A Prehistoric Jewel: Debela Griža Hillfort

Just north of the village Volčji Grad – Wolf’s Castle in the middle of Slovenian Karst – lies a spectacular hillfort that’s not on a hill and is not (as most hillforts aren’t) a fort. It’s called Debela griža – ‘thick heaps of stone’ – due to its humongous walls that dominate the landscape even now, over 3.000 years after they were built.

For a hillfort Debela griža is extremely well preserved, and even if archaeologists describe it as a ‘medium-sized’ enclosure, it is huge: 290 by 180 m, 770 m circumference, 1.100 m of walls, 42.000 square meters of enclosed space.

The earliest archaeological remains from Debela griža date to the middle Bronze age, around 1.200 BC, and the settlement thrived for almost a millennium – it was abandoned in the fourth century BC.

Most ‘hillforts’ were built on top of hills, so Debela griža is rather unique as it sits on a pretty much flat area of Slovenian Karst. Instead of defensive features of steep hillsides people who built it chose a location guarded on three sides by deep dolines (sinkholes typical for a Karst landscape).

Slovenian Karst is a rather flat and open landscape, so one would assume it is a good place to fly kites. It isn’t.

For there is either no wind, or the famous wind of Karst called burja (bora) blows. Burja is a hysterical wind, gusty and strong, with top speeds well over 100 km/h. Even a “light-to-moderate” burja has enough power enough to pull a kite straight out of your hands.

This was our fifth attempt to shoot Debela griža from a kite, with two previous attempts failing because of zero wind, and two because of 50+ km/h gusts. The KAP session was finally a successful one, but we had to fight the wind bringing the kite down (my hands still hurt), and we didn’t dare to fly the kite too high … All in all, we got a lot of photos of this extremely photogenic archaeological site!

As the kite slowly rises, the first thing that comes into view is a deep terraced dolina (sinkhole) with pens for sheep, surrounded by sunken paths and dry stone walls.

And then suddenly a huge wall appears, a thick heap of stone almost 15 meters wide and up to 5 meters high, going into the distance.

A bit higher, and the whole enclosure presents itself: Debela griža. Over 3.000 years old, exquisitely symmetric lowland hillfort.

Debela griža lies on a roughly north-south axis, with entrances at both ends. The northern entrance seems to be lost (the existing entrance was made after the hillfort was abandoned), as is the left (western) part of the inner defensive wall.

The southern entrance and its inner wall is better preserved. There are some indications that towers once stood either right at the entrance or on the point where the outer and the inner wall meet.

As a lowland hillfort Debela griža is rather unique – most hillforts in the area are on, well, tops of hills with great views offering better natural protection. What’s even more interesting, Debela griža was occupied for a very long time, for more than 800 years.

Its walls were enlarged and repaired many times; they are made in a double wall technique – they built two parallel walls from hewn stones and filled the void with rough stone. The original walls were a couple of meters thick and perhaps 6-8 meters high. It is estimated the walls contain over 13.000 tons of stone.

Hillfort interior has been extensively studied with different non-invasive techniques (GPR, electromagnetic, radio) and 11 trenches were dug – but in general archeologists refrain to do more invasive exploration as new generations of experts will have even better methods to unveil everything about this unique site.

Sparse finds show there must have been individual houses built of stone, wood, clay and loam – not unlike the houses on Karst we can still see today.

Local lore knows of a deep pit (a possible cultic area) and a kal, a water reservoir, within the enclosure. Both are long lost; only a comprehensive archaeological exploration could tell us more. If they indeed exist, a true treasure trove awaits.

Indeed, apart from the walls and some chance finds on the surface the hillfort is basically unexplored. Eight centuries of continuous habitation left behind so many stories, but they remain untold – for now.

Debela griža is one of the best preserved hillforts on Karst and in Slovenia in general. After centuries of walls crumbling and stones used for buildings in the nearby village of Volčji Grad the area is now strictly protected. Both the Institute for the Protection of Cultural Heritage of Slovenia, and the local Debela griža Society take care of this prehistoric jewel, preserving it and presenting its beauty to curious visitors.

Debela griža is really worth a visit, so if you find yourself in Slovenia, don’t miss it. The imposing walls, the sheep and goats grazing within them like they used to for centuries, the wind whispering the story of a world long gone – it’s a transcendental experience.

All kite arial photos shot wth Ricoh GR on The Spark rokkaku by Dr.Agon kites, and on The Rokker by SMAC.