Subsurface Imaging of Bilioniai Hillfort, Lithuania

Abstract

Nearly 4,000 potential hillforts exist throughout the Baltic region. Hillforts served multiple purposes, including defensive forts to protect against attack, wooden castles, and settlements. A ground penetrating radar (GPR) study was conducted on a hillfort in the Šilalė district of western Lithuania. GPR is a noninvasive technology that sends high frequency pulsed energy into the ground. A pulseEKKO GPR system equipped with 500 MHz antennae was used to collect a 40m x 20m grid, with the Y-Lines extended when needed. Other tools such as a GPS and a laser lever were used to supplement the GPR data. The GPR data was processed using the software EKKO_Project 5. The results of the grid contain: 1) two rectangular shaped structures with one being 5.2mx11.5m in size, the second is 4.7m x 11.3m in size, both approximately 0.6m-1.4m in depth, 2) linear feature approximately 3.3m long at a depth of 0.75m-1.0m, and 3) two circular shaped objects, one is approximately 2.1m in diameter at 0.15m-0.4m in depth and the second approximately 3.9m in diameter at 1.1m-1.5m in depth. The results will help guide future archaeological excavations and aid in preserving cultural artifacts within the Bilioniai hillfort as well as helping to further explain the history of hillforts.