Ælva

The River ("Ælva" in Norwegian) that runs from Skien and flows into the fjord Frierfjorden, used to be an important transport route through history.

Ælva is the start of the Telemark Channel, which is now one of the county's largest tourist attractions. Along the river and in the estuary, industry started growing, with factories such as Union and Norrøna, both examples of a location with a need for raw material. When you stand on the Porsgrunn Bridge and look up, you can see the river make a sharp turn.

From Skien and downwardsm Ælva follows slanted calcerous layers from the Cambrio-Silurian era, which is clear on a geological map of the area. Suddenly the river takes a sharp turn and goes westward. The reason is that the river enters a large deposition zone, that stretches from Porsgrunn all the way to Kristiansand. When the supercontinent Pangea started fracturing in the Permian Period, this was one of the areas with earthquake-activity and movement. If you look at a satellite image, you can see bodies of water, both large and small, along the deposition zone down towards Kristiansand.