The Venetian fortress of Koules (from the Turkish word "koules", which means "tower, fortress") in Ierapetra, was built in the first years of the Venetian domination. Although, according to local legend, the first fortress on this site was built in 1212 by Genoese pirates and was called Pescatore, and was used as a pirate base. The first written sources that mention the construction of the fortress belong to 1307 and are official documents of the Venetian Senate. In later sources mention the strong destruction of the fortress after the earthquake in 1508. In 1626 under the leadership of General Francesca Morosini were carried out extensive work on the restoration and strengthening of the fortress. The main objective of the fortress was to protect the city's harbour from Arab pirates, and after - and Turkish invaders.

During his reign the Turks contributed to the construction of many architectural changes, but, nevertheless, have left and many Venetian elements. The powerful design of the fortress is fully consistent with their needs on the defensive. The building was used until the 19th century.

Today, the Venetian castle is the landmark of the city of Ierapetra and historic monument that reminds of the past power of the ancient town and its difficult times. Beautiful architectural monument was restored and is now open to the public. Here you can see the well preserved Venetian design and Turkish additions. The Venetian castle is also used for various cultural activities under the leadership of the municipality of Ierapetra.