1) Hadrian's Gate was constructed in 131-132 AD in Athens to honor the Roman emperor Hadrian and mark the boundary between the ancient city of Athens and the new Roman section built during Hadrian's rule. 2) The gate spans an ancient road and is located northwest of the Temple of Olympian Zeus. It is made of marble without cement and features a lower arched passageway and upper triangular pediment. 3) Inscriptions on the gate indicate the areas as the "city of Theseus" and the "city of Hadrian," reflecting the change between the ancient and new sections of the city under Roman rule.