The castle of Kalamata is situated on a hilltop northwest of the modern city. It was originally constructed during the Byzantine times and even an ancient acropolis before the Trojan War. In the beginning of the 13th century Gottfried A Villard, Frank prince and founder of the Principality of Achaea, conducted a large reconstruction of the castle, which resulted to its present form of a typical Byzantine fort.

A shelter-like tower with a vaulted cistern is situated on the wall’s steepest side. There are two fortification zones: the hilltop was protected by the inner fortificationline, while a second outer fortification zone surrounded the accessible and more vulnerable east side of the castle. The fortification walls were developed following the natural terrain and bore bastions, not preserved today. During the second Venetian occupation, which lasted from 1685 to 1715, new alterations and repairs took place.

Among them stands out the reconstruction of the East Gate, where was immured a slab bearing a winged lion, landmark of Venice. In 1825 the castle suffered extended destructions caused by the Ottoman army.

In the 6th century a chuch was built in the castle devoted to Virgin Mary. An icon of here in the church became famous as Kalomata (= “beautiful eyes”). This later evolved to “Kalamata”, which became the name of the church, castle and city.