The Aghios Ioannis basilica in Mastichari is situated at the end of the beachfront walkway, at a distance of about 60m from the sea, and close to the torrent “Glykorriza”. Like most early Christian basilicas in the wider region, the basilica was built between the earthquakes of 469 and 554 AD, as it was a period of relative economic prosperity and devoid of danger from pirate raids, that ravaged the islands from the 7th to the 10th century. Some historians believe it was built on the location of a Temple of Hera. The basilica was long thought to be a church dedicated to St. John. The surrounding area seems to have been inhabited from ancient times, but was abandoned before the 13th century. A lot of stones and remains, like columns, capitals and altarpieces were used in other churches in the region. Unfortunately, in 1945 a kiln was set up next to the basilica that melted marble pieces into quicklime. Eventually, in 1947, the architect Anastasios Orlandos started a systematic excavation of the site, uncovering the architectural, sculptural and artistic marvels, some of which you can explore to this day. The side aisles and the southern structures were dug up in 1955.
This early Christian basilica follows Eastern and African patterns. It doesn’t have an atrium, like all basilicas in Kos except for those in Aghios Stefanos and its roof was made of wood and tiles. It is a tripartite (composed of three parts) hellenistic basilica, with the narthex attached to the west and the large semicircular apse of the altar to the east. The dome shaped baptistry, with a vestibule, is attached to the NE corner of the church, while a three-part structure of the diaconal compartment adjoins the entire south side. The size of the whole structure is 30,3 x 27,7 meters. The walls, 60 to 75 cm. thick, are made of stone although some bricks were occasionally used. Some of the walls still reach the height of 1,50 meters.
The purpose of the narthex, situated at the entrance of the nave, was to allow those not eligible for admittance into the general congregation (particularly catechumens and penitents) to hear and partake of the service. The narthex of the Aghios Ioannis basilica is quite large (14.6×4.65 m), due to the absence of an atrium. The narthex had two entrances, one on the north side of the facade whilst the other was on the narrow southern side of the narthex. Two couples of pilasters that stood opposite each other supported two big crosswise arches that had the same length as the central aisle of the nave. Its wooden ceiling was also the floor of the gallery and gynaikonitis (place reserved for women). The two staircases that led there were located, surprisingly enough from an architectural point of view, in the side aisles of the nave. Remains of one of the staircases are still visible. Three entrances to the three aisles of the nave were located on the east side of the narthex. Two wash-basins, for the symbolic cleansing of hands, were uncovered to the right and left of the central entrance that led from the narthex to the nave.
Nave (central part)
The nave or central part of the Church, without the Chancel’s arch, was 19.90 meters long and 14,60 meters wide. Two archways stood on 19 marble columns along the central axis of the church, separating the nave in three aisles. As is the case of all early Christian basilicas in the Dodecanese, and within the tradition of hellenistic monuments, the colonnade is not interrupted by another orthogonal aisle to form a T, as is the case in most churches nowadays. The central aisle was twice as wide as the side aisles and at a slightly higher level. The colonnades stood upon cube shaped marble pedestals that were probably taken from another Roman monument. Some pedestals are indented because of railings. The columns were 2,06 meters high with an engraved cross. The column capitals were of Ionic order. Only one such column still remains on the site of the Aghios Ioannis basilica, while the others have been transported to other churches in the wider area. The columns supported arches made of adobe or limestone. Numerous windows on the walls above the arches let the sunlight into the church. The balcony had the same length as the nave so one must imagine a two-storey building with a tiled v-shaped roof.
Chancel (space around the altar)
The synthronon and 4 rests of the ciborium (altar table cover) were found in the altar that was pillaged and 9 pillars of the inside colonnades of the church, with sculpted crosses and Ionic capitals with figures, rested on pedestals taken from Roman buildings. A number of ancient columns and artifacts were used as building material and adorn the sides of the structure. Pieces of small square pillars and carved parapets from the marble iconostasis of the basilica were also found.The baptistry of the Aghios Ioannis basilica consists of two chambers, a special vestibule and the main area, with a cross-shaped font. It is square-shaped externally but forms an octagon internally, with 4 semicircular niches and a fifth to the east for the Bishop. It had a hemispherical built roof, whereas the basilica had a wooden one. The baptism was most probably performed by sprinkling or pouring water in white clay jugs, like those that were found in the SE niche of the baptistry. Remnants of multicoloured murals with patterns imitating inlaid marble decorations can still be seen.A number of wonderful mosaics decorate the floors, covering a surface of about 400 square meters, but are currently, for the most part, covered by rubble, to protect them from the weather and decay, so you will only be able to admire the few uncovered parts. With the exception of the baptistry’s vestibule and the chamber of the southern adjacent structure, all floors of the basilica were covered with multicoloured mosaic representations of geometric designs (especially “Syrian wheels” i.e. larger circles joined with smaller cyclical bands), birds, flowers, fruits, vases and eight votive inscriptions in total. The materials used were local marble and limestone, tile and artificial coloured glass mass. Fine sheets of silver were used to cover the tessera of the necks of birds and sheets of gold to cover those of the baptistry’s luxurious inscription.