View looking east along the northern foundation walls of the Temple of Poseidon.
In the seventh century B.C. a temple—Doric style—was built on this site, but most of the current remains date to about A.D. 100. This latest rebuild had 13 columns on its long sides and six on the narrower sides. The sanctuary seems to have ceased functioning the fourth century A.D.
Since Isthmia was inhabited in the Middle Age, no large fragments of the superstructure of this temple are preserved—save those incorporated into a 6 mi. [10 km.] long wall built by the Byzantine Emperor Theodosius II in the fifth century A.D.
For a brief description of Isthmia and a map Click Here.