It was a gated entrance built to secure access to the Parthenon and  other buildings on the Athenian acropolis.    While not intended as a fortification, it controlled… access so that  ritually unclean people could be denied access to the temples. It  also acted as a barrier to criminals and runaway slaves gaining  access to the temples to claim sanctuary. And as the state  treasuries were kept on the Acropolis under protection of the gods,  there was that additional security requirement. (MORE)

Propylaea and North End of Plaza Pan- Am- Exp- - 1901 was released on: USA: June 1901