The area Åssiden was transferred from Lier to the neighboring municipality of Drammen on 1 July 1951.

Norway's longest indoor shopping center, Liertoppen, is located in Lierskogen.

[5][6] Lier borders to the municipalities of Asker, Bærum, Drammen, Modum and Hole.

It includes the villages of Lierbyen, Sylling, Sjåstad, Nøste, Gullaug, Lierskogen, and Tranby.

Lier is thought of as a "green lung" for Norway's capital, Oslo, with its vast number of fields and apple trees.