The very best example of an Athenian dome, a unique masonry of a mid-Byzantine church in Athens built entirely from marble fragments, a true exhibition of sculptures (90 in total) from different historical periods, ancient Greek, Roman, early Christian and Byzantine, make up the “Small Cathedral" of Athens.

 The small church which is located next to the Athens Cathedral and operates as a chapel, with an octagonal dome, semi-complex cross-in-square type, has a long history going back probably from the mid-12th century when it was built, at least according to most experts.

 The temple is dedicated to the Virgin Gorgoepikoos, a Byzantine name of the Theotokos who hears the prayers of the faithful. However, in 1861 A.D. after the failed assassination attempt against King Otto, it was renamed to Saint Sozon (the one who saves), while two years later, with the removal of Otto from the throne of Greece, the temple was dedicated to Saint Eleftherios.

 According to the practices of the Bavarians, from 1834 to 1839 the church was used as an antiquities’ warehouse and until 1962 it was converted into a public library. Today, it stands next to the Athens Cathedral and it is considered one of the most interesting open museums of Athens, with its embedded reliefs on the outer walls and its sides decorated with sculptures, one of the most important among them being the Attic Calendar dating from the 4th century B.C.!