They are distinctive from each other: Hallstahammar-Berg in the north is situated along forest lands; Kolbäck-Säby in the south is a centre of communications by roads and railways as well as the intersecting river.

Strömsholm, in the southern part of Kolbäck, borders Lake Mälaren and has open fields around its Royal Castle.

This is a demographic table based on Hallstahammar Municipality's electoral districts in the 2022 Swedish general election sourced from SVT's election platform, in turn taken from SCB official statistics.

It is also possible to travel straight south, passing the bridge over Lake Mälaren to the larger city Eskilstuna.

Good car transport is provided by European route E18 that passes between Kolbäck and Hallstahammar.