Dadastana (Ancient Greek: Δαδάστανα) was an inland town of ancient Bithynia.[1] The Tabula Peutingeriana places it on a road from Nicaea to Juliopolis, and 29 M. P. from Juliopolis. It appears to have been near the borders of Bithynia and Galatia, as Ammianus says.[2] The emperor Jovianus on his return from the East came from Ancyra to Dadastana, where he died suddenly.
Its site is located near Karahisar, Asiatic Turkey.[3][4]