Salaspils is one of the oldest settlements in Latvia. Archaeological excavations of 1964–1975 (during the construction of Riga HES) in ancient settlements, burial grounds and castle mounds give evidence of very dense population of the region. At this time, the remains of 11,000-year-old reindeer hunters were found (the oldest known human settlement in all of Latvia) and 3500-year-old remains of Baltic hunters, buried in hollowed-out oak-tree trunks, were found as well. There is evidence that both Livs and Balts built hill forts in the region.