A unique monument of folk architecture is the tower of Petmezaia. This famous tower is located in an elevated strategic position in the village of Kalavrita Kato Lousoi.

Simple and imposing, built of grey stone and well-crafted details, it is still preserved in a fairly good condition and is one of the oldest towers of the mountainous Peloponnese (dating back to the 17th century). It is a typical example of a fortified dwelling (with a large number of battlements) and constitutes a unique circular defensive tower in terms of layout and form. A characteristic feature of this tower is the existence of a second, small turret in the south-west corner, an element often found in the tower houses of the mountainous Gortynia and Mani. It was the base of the Petmezai family (who came from Epirus, from where they had to flee because of Turkish persecution) and was the centre of resistance against the Turkish occupation (before the revolution and during the 1821 Revolution). Until recently, the Tower belonged to Vice Admiral and President of the Greek Red Cross Golphin Petmezas and now it belongs to his son Antonio Petmezas, an Officer of the Navy.

The Petmezaians, being famous captains of Kalavrita, played an important role during the Revolution During the Peloponnesian uprising against the Turks and up to 1800, more than twenty Petmezai charioteers and thieves gave their lives in clashes with the Turcovans. Athanasios Petmezas (1760-1804), together with Kolokotronis and Captain Zacharias, created the legendary triumvirate of charioteers in 1785. After the assassination of Zacharias, a sultan's decree was issued placing a bounty on the heads of Kolokotronis and Petmezas. In 1804, Athanasios Petmezas, who had a bounty on his head from the Turks, fell victim to treason and was murdered in his tower.

The Tower of Petmezaians has been officially classified as a historical and listed monument.