Imbrasos (Ancient Greek: Ἴμβρασος, Greek: Ίμβρασος Imvrasos), is a river on the Greek island of Samos. The source of the river is located on mount Ambelos (modern Ampelos or Karvounis), near the village of Pyrgos[de]. From there it flows southeast to Myli[de] and then enters the sea on the south side of the island at Ireo[de]. In ancient times, it had the epithet Parthenios ('of the maiden'), because the goddess Hera was said to have been born on its bank under a lygos tree. The site became the Heraion, which was the main ancient sanctuary on the island.

The river god Imbrasos was often depicted on Samian coinage, sometimes holding a peacock. In mythology, his wife was the nymph Chesias. Their daughter, Ocyrhoë, was loved by Apollo.

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