This is actually one of the very last (maybe even the last) visible remains of the archaic age on the acropolis cliff in Athens.
As you might expect, this picture holds more than the eye might see at first. Notice the huge stone drums that the wall is built up by - these are column drums.
There was, before the Parthenon was built another temple planned. The foundation was laid out before the outbreak of the second Persian war (480-479) but raised when the enemy took Athens. Some of the gathered material was found to be useful still when the constructed of the Parthenon was begun some 30 years later, some other parts were deemed useless. These useless pieces was the incorporated into the cliffs defensive walls, seen here at the north side of the acropolis. They can also be seen at the top of the cliff if you walk by the wall.