Turkey is a contiguous transcontinental country. Its larger part is in Western Asia, and the smaller in Southeastern Europe. Turkey is a democratic, secular, unitary, constitutional republic with a diverse cultural heritage. The country's official language is Turkish, a Turkic language spoken natively by approximately 85% of the population. Turkey is bordered by eight countries: Bulgaria to the northwest; Greece to the west; Georgia to the northeast; Armenia, Iran and the Azerbaijani exclave of Nakhchivan to the east; and Iraq and Syria to the southeast. The Mediterranean Sea is to the south; the Aegean Sea to the west; and the Black Sea to the north. The Sea of Marmara, the Bosphorus and the Dardanelles demarcate the boundary between Thrace and Anatolia; they also separate Europe and Asia. Turkey's location at the crossroads of Europe and Asia makes it a country of significant geostrategic importance.