The building was erected and used as the tomb of a prominent Roman official (procurator) who is depicted in the medallion of the pediment. Perhaps he was responsible for the supervision of the Roman quarries to the north of Karystos. After the first investigation of the site (excavation in 1908), the building was interpreted as a temple dedicated to a deity, possibly Apollo, Artemis of Hephaestos.
It is a peristyle, almost square, temple-like building, built of good quality marble (white pentelic, and greyish karystian cipollino). It measures 13.20 x 12.30 m. and is surrounded by an Ionic colonnade of 7 x 6 columns.It stands on a five-stepped base, partly preserved, and has a cella entered from the south (as the whole building is), looking towards the harbour. One oof the steps runs along the walls of the cella, and the sarcophagi were probably placed on it. The pediment was decorated with the bust of the deceased and a horse, in a circular medallion (imago clipeata). The monument is dated to the Hadrianic-Antoninian period (middle of the 2nd century A.D.).