The unfinished walls of the Birg

The Birg is an Unsternwall, a hillfort and section fortification near Kleinhöhenkirchen in the municipality of Weyarn. Located in the Mangfallknie in Upper Bavaria, the site sits at the beginning of the Grub-Harthausener dry valley on the inside of a bend of the Mangfall river. The fortification dates back to the Middle Ages, likely to the 10th century.

The site is officially recorded in the Bayernatlas as a multi-part section fortification from the Bronze Age, Urnfield period, Hallstatt period, and the Carolingian-Ottonian period. Evidence suggests that the construction of the Birg was never completed. Natural steep slopes provided protection to the east and northwest, making artificial structures unnecessary in those areas. To the south, a plateau is separated from the interior by two ramparts.

The southwestern side is protected by a system of ramparts and ditches consisting of three lines. Wall I in the south is approximately 300 m long with a curved course. It has a notch in the middle with a preceding earthen ramp. The crest of the wall rises up to 10 m above the surrounding terrain and towers over the interior by up to 7 m. A modern access road cuts through the middle section of Wall I, while Wall IIIa joins its northern end.

The interior of the Birg has two rooms measuring approximately 330 m in the north-south direction and between 100 and 200 m in the east-west direction. The southern part of the interior is bounded by an inner south wall, Wall II. Wall II reaches heights of up to 8 m above the southern interior and 3 m above the northern interior, ending at a steep slope in the east. In a northwest direction, Wall II continues as Wall IIIb, which is intersected by a modern path.

Various wall segments are located in front of Wall III, with the southern segments of the wall ending on a single line. Two outer ditches are located in the east of the wall, with a smaller ditch in the west. Today, the Birg remains a notable archaeological site where the layout of the ancient earthworks remains visible despite the unfinished nature of the construction.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons