It is located in the province of Western Finland and is part of the Satakunta region. The town has a population of 7,268 (31 March 2016) and covers an area of 123.46 square kilometres (47.67 sq mi) of which 4.28 km² (1.65 sq mi) is water. The population density is 58.87 inhabitants per square kilometre (152.5/sq mi).

Today people in the town are employed in the copper and nickel smelting industries. Today's most used metal recovery method, the flash smelting method, was developed at Harjavalta and implemented in 1949. Originally part of Outokumpu, a Finnish company, the copper business is now owned by Boliden and the nickel business by Norilsk Nickel.

Earliest signs of habitation have been dated to 1200 BC. Written records mentioning the then village begin in the AD 15th century. Origins of the name Harjavalta go back to Chariovald, a German warrior chief quoted by the Roman historian Tacitus. The Germanic word harja-walduz denotes warrior chief and was adopted into Scandinavian languages in various forms. It is believed that either a person named Harjavaldus or a warrior band settled or lived in the area.

Hiittenharju is a valuable area for its archaeology and cultural history. You can visit the banks of the ancient Litorina Sea on the fringes of the ridge Hiittenharju and the graves of the Bronze Age, called barrows. In Hiittenharju there is also a historical route called Huovintie running through Harjavalta.

The river Kokemäenjoki river runs through the town.

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Wikipedia