Therma or Thermē is the unknown city incorporated into the new city of Thessaloniki by the Macedonians on its synoecism and foundation. Little is known of literary Therma, including its exact location
Herodotus says that Xerxes, Persian invader of Greece in 480 BC, could see Mounts Olympus and Ossa from Therma. They were two mountains in Thessaly across the Thermaic Gulf. This view from Thessaloniki, looking southward along the shore at Mikro Emvolo, seems to fit. It is intermediate in distance between the two habitation sites believed to be possibly ancient Therma. The coordinates given here belong to this coastal point.