The Catacombs are the subterranean cemetery of the first Christian centuries in Melos. Located on the hillside southwest of the village of Tripiti in the area of the ancient city?s ruins of the seaside village of Klima. In the area, there are smaller underground cemeteries, in the form of Catacombs.

The Catacombs were known locally as «the Greek cave». The Catacombs had suffered looting long before German archaeologist Ludwig Ross visited the site in 1844. French archaeologist Ch. Bayet visited the Catacombs in 1878 and George Lampakis in 1907 until they were systematically researched and studied by Professor George Sotiriou in 1928. They are a complex of spacious halls and corridors carved in soft porous volcanic rock (ash), and connected via artificial corridors. The cluster completes a family burial chamber (cubiculum). Initially, G. Sotiriou had considered that there are three originally independent Catacombs, A, B and C consisting of rooms and corridors. The total length of the galleries is about 200m., with its width varying between 1-5m and its height from 1.6-2.5m.

Two types of tombs have been carved into the walls, the arcosolia (arched) and the loculi (horizontal recesses). Pit graves have been carved into the ground.

Slabs of different sizes covered all tombs. Some arcosolia save painted decorations and fragments of inscriptions on the drum or conch for depositing offerings and lamps, and in some cases for the burial of infants.

The current entrance is located in the Hall of Catacomb B. On the right side of the room, the unique two-storey arcosolium is preserved and fragments of the important inscription of «Elders», written in red capital letters on a rectangular framework (tabula ansata). In the middle of the hall an individual above-ground tomb-shaped sarcophagus has been carved, known as «Tomb of the Witness». The tomb was probably used as an altar with ciborium, as, above the grave, traces of capitals were found in 1928 by G. Sotiriou.

To the west of the Catacomb B lies a second room of Catacomb A. On the north side, arcosolia have been carved in pairs. There are probably family graves. In the corridor 1 which is not accessible, there are fragments of two inscriptions in rectangular frame (inscriptions of «Melon» and «Thomas»).

To the east of Catacomb B lies a family burial chamber (cubiculum) and the Catacomb C, not currently accessible. The cubiculum incorporates on its sides three arcosolia and a cist tomb. The southern part of the Catacomb C has collapsed and the two halls are connected by an artificial corridor. In two arcosolia of corridor 2 there are fragments of a scene with flowers and two birds, the Christogram and the letters Ω and A.

The excavations conducted during 2007-2009 by the 2nd Ephorate of Byzantine Antiquities revealed the southern part of the chambers of Catacomb A and B to a length of approximately 1 5 m. The roof had almost completely collapsed; however, the walls are intact along with nine arcosolia and four loculi. The two halls are connected by a transverse corridor, which refutes Sotiriou?s opinion that Catacombs were three independent galleries.

Over the remaing southern part of the Catacomb B a new small cubiculum has been revealed. Apart from the arcosolia two cist graves, a marble sarcophagus and thirty three pit graves were revealed. Most of the excavated graves have been plundered or disturbed. They were covered with heavily processed slabs of different sizes and successive layers of plaster. The pit graves were either simple or housed a second chamber in the type of arcosolium. Today none of the cist graves is visible because they have been covered for preservation purposes.

Few graves gave valuable gems, such as pendants, a metal ring, glass vessels and glass beads. Bronze and iron nails were also found. Throughout the entire excavation lamps also were found. Traces of fire, pottery sherds from cooking pots, jugs, plates and animal and fish bones were found declaring that nekrodeipnon and other burial rites were been taken place.

To the west of the hall of the Catacomb A, a new hall was revealed («Hall Bayet», XII) but has been temporarily closed off for protection. The original entrance of the hall is located in the northwest. Nine arcosolia and two cubicula have been carved into its walls.

In the south, where the walls of the Catacomb A and «Hall Bayet» converge, a semicircular wall came to light and an unfluted column has been revealed in situ. These findings suggest that this is probably one of the primary entrances of the Catacombs.

The findings and grave offerings, that were revealed, date the use of the cemetery from the mid first century AD until the 6th century AD.