The banks of the ancient Litorina Sea lies on the fringes of the Hiittenharju ridge.

Various different writings of the name in documents of the 15th century at the Turku Cathedral are Harianwalta, Hariawalta, Hariaualdastha, Harianwaltha and Harianwaltaby.

It is believed that either a person named Harjawaldaz or a warrior band settled or lived in the area.

[5] Different adoptions of the same name are Harald, Hérault and Harold, but Harjavalta is closest to the reconstructed original.

In 1670, the villages of Harjavalta formed their own chapel parish, but the official status of an independent congregation began to be sought about 200 years later.

The most important sales products were salt, coffee and sugar, but the selections also included fabrics, wheat flour, licorice and tobacco.