The geological uplift after ice age has been relatively high at the mouth of the Kokemäenjoki river. 1558 when the city was established it was situated on the shore of Pori bay. Because of this uplift the delta of the river begins now on the front of the city. Recreation area of Kirjurinluoto is actually on an island connected with bridges to mainland. Pori National Urban Park preserves the story of the phases of development of the town born at the mouth of the river Kokemäenjoki
