The temple is the Erechtion (built 421-406 BCE), which housed cults of Athena Polias (Athena of the City) and Poseidon.  In the foreground are the ruins of the Old Athena Temple (built in the late 6th century), which was destroyed by the Persian invasion of 480 BCE.  The hill in the background is Mt. Lykavittos, capped by an 18th century church of St. George (Ayios Yiorgos).

(Photo by: Alex Knodell)