According to Forte, Oram, and Pedersen, "The Illerup Ådal site is one of twenty-five in Denmark and southern Sweden where weapons were sacrificed." The sites include eastern Jylland, Fyn, Lolland, Sjaelland, and Bornholm in Denmark, plus Gotland and Smaland in Sweden. The oldest deposit in Illerup Ådal contained 300 spear points with the name Wagnijo written in runes, plus shields, belts, and scabbards. In addition, about 129 tinderboxes, and 124 combs were unearthed.[1]

The first archaeological findings at the river valley of Illerup Ådal were revealed in 1950, during some drainage work. The area was subsequently excavated from 1950 till 1956 and again from 1975 to 1985. During the excavations more than 15,000 items, mainly Iron Age weapons and personal equipment from 200 to 500 AD, were found. It is generally agreed that the findings are enemy equipment captured after victories, and then thrown into the lake, as a votive offering to the gods. Illerup Ådal is one of twenty-five sites in Denmark and Southern Sweden where sacrificed weapons have been found.

Archeological excavations also produced some findings bearing the Elder Futhark runic inscriptions from the earliest period.

To ensure preservation of the area, which still holds many findings, the location was granted protected status in 1996.