Agios Eleftherios Church, Athens

The Panagia Gorgoepikoos, the Virgin Who Hears Quickly, is a small Byzantine cross-in-square church in central Athens, tucked into the square beside the large Mitropolis Cathedral. Built in the 12th century, it is among the most completely preserved middle Byzantine buildings in Greece. Its defining feature is the 90 or so spolia worked into the exterior: antique reliefs, Hellenistic friezes and early Byzantine carved panels that the builders gathered from older structures. The result is a facade that functions as an open-air museum of ancient and Byzantine sculpture. The church is not always open inside, but a walk around the outside is well worthwhile, especially combined with the adjacent cathedral and a stroll into Plaka.