Bilionys hill fort in the Šilalė District () was first suggested by German historian Johannes Voigt. This version is supported by Stasys Kasparavičius who noted that Bilionys is sometimes known as Pilionys and is very similar to Pillenen mentioned in written sources. Additionally, Bilionys is located just south of Medvėgalis which was attacked in 1329 and also likely defended by Margiris. Bilionys must have been a large and strong fortress as its upper bailey but there is no mention in written sources that it was attacked while neighboring hill forts were attacked several times. However, etymological connection between Bilionys and Pilėnai is dubious as the toponym Bilionys likely derived from a personal name. Nevertheless, since 2012 Verkiai Regional Park organizes events to commemorate Pilėnai on Bilionys hill fort.