On the west breakwater of the ancient port of Lechaion remains of the big scale early Christian Basilica are still preserved, dedicated to the martyr Leonidis and the seven women that were martyred with him. In the area, the site is also known as “Lechaion Basilica”.
The foundations were laid in the 5th century A.D. and the construction was completed under the rule of Justine I (518-527 A.D.) .Unfortunately, the glamour of the monument did not last, since in 551/552 A.D. it was completely destroyed by a very powerful earthquake.
Leonidis Basilica is a three-aisled basilica, measuring 91 meters by 27. The building consists of an aisle with five parts, two corner apartments, a semicircular arch, a five-part narthex and two atriums. On the outside, the building complex was 220 meters long and 59.29 meters wide.
The two atria at the entrance, a rectangular and a circular one, were surrounded by a stoa. A phiale with fountains was located at the semicircular atrium where the pilgrims had to wash before entering the church. The entrance to the narthex, the main place of prays and religious education was accessible by two different entrances. Three openings permitted the communication between the narthex and the main church.
Two colonnades, each containing 23 columns, divided the main church ino three aisles. In the middle of the central aisle there was an octagonal ambo with stairs on both sides. At the east part of the church, the bema, is the synthronon and the clergy benches, while the altar was covered by a ciborium.
Parts of the stylobate that extended throughout width of the middle aisle have been preserved from the altarscreen. The solea began from the center of the altarscreen. It consists of a long corridor formed by two parallel rows of marble stylobates with piers. The solea ends at the ambo of the middle aisle.
The trifold baptistery was located at the northwest corner of the church. It consisted of an independent complex with a forecourt edifice, an apodyterium and an octagonal baptistery with two built baptismal fonts, one shallow for adults, sprinkling baptism, and a deep one for the kids where the baptism was made by immersion. The complex was older than the basilica and architectural autonomous. It was probably a mausoleum.
The early byzantine basilica of Leonidis was built with special assiduity. The ornamental trowelings on the joints. The roof on the middle aisle must have been saddle, and lean-to at the side aisles. The central part of the sanctuary had a hipped roof.
The floor was paved with marble white slabs, while the marble inlays of the side aisles and the columns presented a variety of colors (white, vermilion, gray, green).
The sculpted decoration presented a great variety and quality. Numerous samples of the decoration lie sparse at the site and the Archaeological Museum of Ancient Corinth. These include Corinthian capitals, Ionic capitals with imposts, Theodosians, imposts, crowns and door frames with rich decoration. Additionally there are, columns, slabs, column bases, and numerous other elements.