The mighty and mysterious hillfort of Semigallians – Silakalns – is surrounded by forests. The findings on the hillfort link it to the late Iron Age, while the ceramics fragments demonstrate that the hillfort was inhabited already in the 1st millennium BC. Historians have several hypotheses about Silakalns. According to one assumption, it is deemed as the main fortification of the Land Silene, as cited by Semigallia land division agreement of the 13th century. Getting to the hillfort will be a real adventure, since Silakalns is located in the forest, is overgrown with coniferous trees and bushes, and a swamp encloses it on its south and west side.