Port’s lighthouse is right across the entrance of the central port, in the small island Didimo or Gaidouronisi. It was built in 1834. It has a height of 29,5m and by making this gigantic lighthouse, the residents of Syros, wanted to point the master role of their port in Greece.
This was the first lighthouse with a revolving machine in Aegean Sea and had big range. It is said that its light reached the coast of Asia Minor.