Tolosa is a town and municipality in the Basque province of Gipuzkoa, in northern Spain. It is located in the valley of the river Oria, next by Uztā¦Tolosa is a town and municipality in the Basque province of Gipuzkoa, in northern Spain. It is located in the valley of the river Oria, next by Uzturre, a local mountain topped by a white cross. Its economy relies primarily on the industrial sector, specifically papermaking.