The Kaupiškiai hillfort is located on the northern side of the undulating Sūduva highlands, near the former Prussian border. It is like a middle ground between the undulating plains of Suvalkija, where the lowest point reaches only 30 m above sea level, and between the hills of this region, which stretch into the sky as much as 282 m above sea level. On the relatively high hill, 135.6 m above sea level, people were already living in the first millennium. During archaeological research, the remains of rough and smooth pottery were found. Jonas Basanavičius already mentions the hillfort in the first pages of "Autobiography", as one of the other castles built here in the 13th-14th century, and maybe even earlier, to defend against unexpected robbers.