A hillfort Libna near town Krsko in Slovenia. A map overlaying 3D LiDAR model shows all known mounds dating to Iron Age/Hallstat.
Map copied from
Dular, J. 2006, Zeleznodobno naselje in grobisce na Libni, Arheoloski vestnik 57, str. 163-183
LiDAR data
http://gis.arso.gov.si/evode/profile.aspx?id=atlas_voda_Lidar@Arso