Nemea is known thanks to the first of the twelve works of Hercules. Close to this place the mid-God killed the wild lion of Nemea in its cave. It is possible that the legend has a bit of truth because Mycenaean images suggest lions lived in the area during that time.
On the archaeological site, remain some vestiges and columns of the temple of Zeus from the IVth BC.
Photos from Nemea
Temple of Zeus, 6x12 columns, IVth BC