The Hercules Gate
From a specialist site on Ephesus I quote: Located towards the end of the Curetes Street, it was called the Hercules gate because of the relief of Hercules on it. It was brought from another place in the fourth century AD to its current place, but the relief on it dates back to the second century AD.
Only the two side of the columns remain today and the other parts of it have not been found. The relief of the flying Nike in the Domitian Square is thought to also be a part of this gate.