You can observed the famous Evripos tide in the Evripos strait in Evia.

The Evripos tide is a unique phenomenon that occurs in the strait of Evripos. At this point, water runs constantly changing direction of movement about every six hours, sometimes to the South and sometimes to the North with Evian Gulf as an intermediate small space where they remain stationary. This constant motion gave the sea and the area the nickname "crazy waters".

This phenomenon has been observed since ancient times, puzzling some of the leading thinkers of the era, such as Eratosthenes and Aristotle. Actually, it is said that he dived into the waters trying to solve the mystery of their motion.

Today the accepted explanation for this very special phenomenon is that the Aegean tidal wave enters the northern and southern Gulf of Evia with time difference, thus creating this spectacular movement.

Whatever the explanation, this is a very special and beautiful phenomenon worth seeing first hand when you find yourself in Chalkida.