D.400 is an east–west state road in southern Turkey. The 2057 km road starts at Datça in the southwest corner of the Anatolian peninsula and ends at the Iranian border at Esendere. D.400 runs through the cities of Marmaris, Fethiye, Antalya, Alanya, Mersin, Adana, Gaziantep, Şanlıurfa, and Hakkâri and links to Road 16 in Iran. Between Nizip and Cizre, D.400 is part of the European route E90.

Itinerary

The table below shows the locations between Datça and Esendere. {| class="wikitable" !scope="col"|Province !scope="col"|City !scope="col"|Distance from previous location !scope="col"|Distance from Datça !scope="col"|Distance from Esendere

Intersections

• at Gökova • near Dalaman • near Fethiye • near Finike • at Antalya • near Antalya Airport • at Bereket, Antalya Province • near Kızılağaç, Antalya Province • at Silifke • near Erdemli • at Adana • at Çakaldere, Adana Province • at Ceyhan • near Tüysüz, Osmaniye Province • near Tüysüz, Osmaniye Province • at Nurdağı • near Gaziantep • at Gaziantep • at Gaziantep • at Nizip • at Şanlıurfa • at Viranşehir • at Kızıltepe • at Cizre • at Şırnak • near Bağışlı, Hakkari Province • at Serow, West Azarbaijan