Church of the Holy Apostles / 2 images

The only medieval building in the Ancient Agora that has been preserved, situated partly over the much earlier Nymphaion. In a Byzantine style, early C11AD, restored 1950s. Athens, Greece.

The dome is the oldest example of the Byzantine Athenian type and the twin-light windows in the drum are considered unusual. The painting of the 'Pantokrator' (The All Powerful) is late C18 restoration work. 

(both images CC BY-NC-SA)