A 228 m hill, picturesquely surrounded by four lakes and other knolls. Together with Church and Cemetery Mounts they formed Jadzvingian defensive position (VII – XIII century).Mount Zamkowa – natural conically shaped moraine hill situated in Czajewszczyzna village. It is 228,1 m above the sea level, that is 45 m above the level of the four surrounding lakes. From the flat summit there are magnificent views of the lakes lying at its foot: Szurpiły, Kluczysko, Jeglówek , Jeglóweczek and surrounding post-glacial hills. These natural fortifications had been used by Jadzvingians who set here up a fortified medieval settlement and one of the tribal centers of early medieval Jaćwież.
Jaćwież used to stretch out from Great Mazurian Lakes on the west, to Neman River on the east, Szeszupa drainage on the north and Biebrza on the south, including what we call today Suwalszczyzna. At present Mount Zamkowa with other objects of the fortified medieval settlement (Mount Church, Mount Cemetery, Hermitage Island) is one of the most interesting complexes of that type in north-east Poland.