Harju County , or Harjumaa (, ) is one of the 15 counties of Estonia. It is situated in Northern Estonia, on the southern coast of the Gulf of Finland, and borders Lääne-Viru County to the east, Järva County to the south-east, Rapla County to the south, and Lääne County to the south-west. In January 2015 Harju County had a population of 575,601 – constituting 43.8% of the total population of Estonia. Tallinn, the capital and largest city of Estonia, constitutes about 72% of the county's population with its 413,782 inhabitants.