East Thrace includes two narrow straits, provides access to the Mediterranean from the Black Sea for the navies of five countries: Russia, Ukraine, Romania, Bulgaria, and Georgia. The region also serves as a future connector of existing Turkish and European high speed rail networks. East Thrace includes all in the eastern part of the historical region of Thrace. The area includes all the territories of the Turkish provinces of Edirne, Tekirdağ and Kırklareli, as well as those territories on the European Continent of the provinces of Çanakkale and Istanbul. Due to the moderating effect of the surrounding seas, the climate tends to
Geography of Turkey of the sizable Greek-speaking community of western Turkey were forced to resettle in Greece, while the majority of the Turkish-speaking residents of Thrace who were not forced out during the Balkan wars were removed to Turkey. The boundary with Bulgaria was confirmed by the Treaty of Lausanne (1923). Since 1991 the more than boundary with the former Soviet Union, which was defined in the 1921 Treaty of Moscow (1921) and Treaty of Kars, has formed Turkey's borders with the independent countries of Armenia, Azerbaijan, and Georgia. The boundary with Iran was confirmed by the Treaty of Kasr-ı Şirin in 1639.