At the far north end of the promenade of Santa Marina, on the island of Salina, you can visit part of a Roman-age spa complex, in use during the first centuries of the Imperial Age, and reused in late Roman times (at least until the beginning of the 6th century AD) as a factory for processing and salting fish, mainly sardelles, for the production of garum, a sauce of fish entrails and salted fish that the ancient Romans added as a condiment to many first and second courses.
An alluvial deposit of sand and volcanic stones, derived from Monte Fossa delle Felci, covered the levels of abandonment of the brickwork structures.
The entire complex is now damaged by erosion caused by atmospheric agents and frequent sea storms, favoured, over time, by the gradual reduction of the beach.
Of the spa building the long front wall is visible with short sections of the walls perpendicular to the rooms, built with pebbles and mortar and covered with plaster that was also painted, traces of which are preserved in one room. On the southern side there is a strip of the calidarium or hot room with the hypocaust, consisting of heat-resistant stone pillars and terracotta bricks, where the hot air circulated to heat the water in the pool above.
In the central area there is a larger pool, which was accessed via three steps on the southern side, intended for bathing in warm water (in the tepidarium) or cold water (in the frigidarium).
In late Roman times all parts of the building were reused. The construction of new walls brought about changes in the general plan, while in the upper terrace the rooms were filled with earth and stones and the floor level consisting of terracotta slabs and tiles was raised. To process salted fish, numerous tanks of various shapes and sizes were installed and some of the pools of the spa were reused. The well leaning against the front wall of the spa, visible in the central part of the excavation, also belongs to this phase. It can be hypothesised that the salted fish industry in the Barone district was related to the salt mine found in the small lake in the hamlet of Lingua, around 6 km away, also in use in Roman times.
