Hiiu County The smallest county in Estonia(pop. 10,000). is the smallest county out of 15 counties in Estonia(population approx.10,000). Hiiu County The smallest county in Estonia(pop. 10,000). consists of Hiiumaa Second largest island in the NW of Estonia(pop.10,000). island and other smaller islands around it. The county is bordered by Saare County County in SW of Estonia(pop. 35,000). in the south and Lääne County County on the west of Estonia (pop. 25,000). in the west.