Selymbria (Greek: Σηλυμβρία),[1] or Selybria (Σηλυβρία),[2][3][4] or Selybrie (Σηλυβρίη),[5] was a town of ancient Thrace on the Propontis, 22 Roman miles east from Perinthus, and 44 Roman miles west from Constantinople,[6] near the southern end of the wall built by Anastasius I Dicorus for the protection of his capital.[7] Its site is located at Silivri in European Turkey.[8][9]