A short distance from Messolonghi, in the location of ‘St. John’, survives a large and imposing complex of public baths from Roman times. The monument was known in Anglo Browser WM Leake, who identified it as the Roman Baths.

Some scholars put in place this ancient Elao or Oil, referred to by the historian Polybius, when describing the advances of the Macedonian army under Philip V by Oiniades to South Aetolia in 219 BC, while others believe that it served as a military installation or camp.

From the bath complex they have identified a large rectangular pool for the cold bath (Frigidarium), coated with hydraulic plaster on the side walls and colored marble slabs on the bottom, a central space with four built-cylindrical tubs (alvei) to lukewarm bath (tepidarium), the floor of which was also covered with marble slabs, a number of small areas of various shapes formed in a whirlpool for hot bath (Caldarium), hypocausts (hypocausta) and praefurnia (spaces, wherein heated water). Another room is synonymous with changing room (apodyterium) and another with sudatorium, room where the sweating was taking place. The feeding of the baths with water was done by two major built rectangular tanks.