Chalkida (or Chalkis) is a Greek town. Its population is 55,264 inhabitants according to the 2001 census. Chalkida is located to the north of Athens, on Euboea island. It is at the point where the Euboea is nearest to mainland Greece. At this point is the Eyripous narrow, a sea narrow, where there is a tidal phenomenon.
During antiquity, Chalkida was an important town. Its people were Ionian, an ancient Greek race. Chalkida had founded many colonies. Most of them were in south Italy. The Latin alphabet is an evolution of the ancient Chalkidian alphabet. During the Middle Ages Chalkida was an unimportant city. During the Lombardian knights' rule, Chalkida was developed again. Today Chalkida is an industrial town.