The Metropolitan Cathedral — usually just called the Mitropoli — is the seat of the Archbishop of Athens and All Greece. The current building, finished in 1862, is a large but not particularly interesting 19th-century structure. It is the small church beside it that draws the visitors: the Little Metropolis (Panagia Gorgoepikoos), an 11th- or 12th-century Byzantine miniature built entirely from re-used ancient and early-Christian stones.
Examine the masonry of the little church carefully and you can pick out classical friezes, Roman inscriptions, and Byzantine carvings all set into the same walls — a building made from the rubble of two thousand years of Athenian history.