The mound (Pilalė) is located on a separate hill on the edge of the upper terrace of the Nemunas. The site is oval, elongated in the S – N direction, 37x23 m in size. The slopes are steep, 10 m high. Later, a cemetery appears to have been installed on the site. The castle is surrounded on all sides by ravines and overgrown with bushes. It is sometimes mentioned in the name of the village of Geležūnai, because it is like a border between two villages. At the mound in 1888. E. Volter excavated in the 15th-16th centuries. ancient burial ground, and Roman coins were found. 1971 the mound was explored by the institute of history.
The mound dates back to the 1st thousand.
Accessible from Prienai – Trakai highway (A16) at Būdai turning to Nemajūnai, without reaching them after Geležiūnai, descending to Nemunas valley, turning right (V), after 300 m (is 100 m to the right (Š), to P from the power line) .
Literature: Milušauskienė Ramutė. 2017. Mounds in the Nemunas Loops Regional Park. Kaunas