The Thespian fortress is located in the Municipality of Thestia, in an altitude of 688 meters. On the top of the homonym hill, on the west slope the Panaitoliko Mountain, there was the ancient city of Thestia, as indicated by the Hellenistic walls that are still preserved in the area. The city bears the name of the mythic king Thestios. The walls protected the city from the south and the east of the acropolis.

The fortress of Vlochos is a Byzantine construction that was given as dowry to Phillip of Tarantas in 1294. It was occupied by the Turks in 1450 and was later abandoned. Nowadays, the remains of the fortress are found.

In the beginning of the last century, G. Sotiriadis, professor in the University of Athens, conducted many excavations in Vlochos, as well as in many other regions in our municipality.

Right under the acropolis of Thestia there is the monastery of Vlochos, dedicated to the Assumption of Mary ("koimisis tis Theotokou"), featuring old and contemporary buildings, including the 18^th century temple of the Assumption of Mary (a basilica type construction with an elaborate wooden roof and iconostasis).

The Monastery was founded somewhere between the end of the 12^th and the beginning of the 13^th century.  According to a 1563 document, the monastery was reconstructed in the mid-16^th century. When the Monastery was shut down by order of the king Othon, all its relics were moved to the Monastery of Proussos. Nowadays, only a few relics are preserved, including a communion cup, a gospel, a feretory and the stamp of the Monastery.