The fortress with the round tower is the smaller of two fortresses located in the small town of Mardakyan, to the northeast of the Aspheron Peninsula and was also constructed earlier, in 1232. It is part of a series of fortresses and castles along the peninsula coast that created a unified defensive system against assaults from the Caspian Sea.
The fortress consists of rectangular ramparts that enclose an inner courtyard of twenty-five per twenty-five meters and a round tower, of sixteen meters height, rising at the center. The tower has three floors connected with a spiral staircase. It was initially considered to be a freestanding tower, until the remains of its ramparts were unearthed during excavations.
It closely resembles the Fortress at Nardaran and the Djebahan Castle in Baku. Both Mardakyan fortresses are completely restored and preserved.
Aslanapa, Oktay. 1979. Kirim ve Kuzey Azerbaycan'da Türk Eserleri. Istanbul: Baha Matbaasi, 57.