The Bilioniai Hillfort (Švedkalnis) was formerly known as Šventkalnis. Local residents say, "In the past, it was not called Švedkalnis, but Šventkalnis. In the past, sacrifices were made there. Then the Swedes occupied the hill and built a fortress on top of it." It is also said that a Swedish unit settled on the hill and robbed the local residents, but disappeared one summer night. The hillfort dates back to the period of the wars with the Teutonic Knights. Due to the clearly visible remains of the hillfort's defensive fortifications (terraces), it resembles a stepped pyramid. The southern slope has a rich cultural layer – pottery with a rough surface has been found. The famous archaeologist L. Kšivickis was so impressed by the Bilioniai hillfort that he named it one of the most interesting archaeological monuments not only in Lithuania, but in the whole world. The hillfort rises 203 m above sea level.