The first-millennium fortification of Obonių piliakalnis

Obonių piliakalnis, also known as Zūbiškiai, is an archaeological fortification located in the Kupiškis district municipality. It is situated to the northwest of Vairiškių, in the Šimonių eldership. To reach the site, travelers follow the road from Adomynė to Juodupėnai, turning right towards the east at the second farmstead of Obonys village. It is situated in a marshy birch forest approximately 500 metres to the east of this point.

The site is difficult to find because the forest is very dense, marshy, and lacks large landmarks. The fortification consists of a low hill in a swampy area, described as an island. It features an oval clearing, 24 by 30 metres in diameter, oriented north-south. The clearing is bordered by a 0.3 metre high and 3 metre wide earthwork. Further down the slope, 3 metres below the clearing, are the remains of a second fortification wall measuring 140 metres long, 0.6-0.8 metres high, and 4 metres wide. The slope itself has an average height of 8 metres.

Covered in wild garlic and birch trees, the site dates back to the first millennium. It was included in the list of Lithuanian cultural monuments in 1973 and registered in the Register of Cultural Values in 1992. The site was officially declared a cultural monument by a Government of the Republic of Lithuania decree in 1998, with further regulations regarding its cultural value confirmed in 2007. The total area of the monument territory is 0.59 hectares.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons