Zemnen in the meaning zemný hrad (literally 'the earth castle', earthwork) was still recorded in the early 14th century.
The original Slavic form has been preserved in the local Slovak and Ruthenian dialects as Zemno, Zemné resp.
[4] The Slavic hill fort is mentioned in Gesta Hungarorum, describing how legendary chieftain of the Hung (Uzhhorod) castle fled "ad castrum Zemlun".
The continuity of the population has been preserved also after the fall of Great Moravia and the Slavic settlement of the hill fort is documented between the 9th and the 12th century.
Nowadays, the area is a part of the village and is occupied by two churches (Greek-Catholic built 1804 and Evangelical rebuilt in 1628) and the modern cemetery.