Between Petalidi and Koroni lies Agios Andreas, the seaport of Longa, where part of the sanctuary of Apollo Korythos was excavated by Frederikos Versakis in 1915. The sanctuary was founded in the 8th century BC and remained in use until the late Roman times. Later, a Christian temple was built on the same site. The excavation uncovered five buildings used for cultic purposes. The 6th century BC peripteral Doric temple is particularly noteworthy. It consists of a pronaos (porch), a cella, an adyton (rear room) and an opisthodomos (rear porch).

Epigraphic evidence suggests that during Roman times, a triclinium, i.e. a restaurant with three reclining couches was used for religious banquets. Votive inscriptions identified the worshipped deity as Apollo Korythos who was worshipped as both a warrior with a helmet (korys) and a healer. Among other findings, bronze offerings, such as figurines, weapons, tools of the 6th and 5th centuries BC, stand out. These items are of obvious Laconian style and sometimes feature inscriptions in the Laconian alphabet. Today, most of the sanctuary’s findings are exhibited in the National Archaeological Museum in Athens and the Archaeological Museum of Messenia in Kalamata.