ANCIENT CITY OF MEGALOPOLIS MARKETPLACE AND CIVIC BUILDINGS On the north bank of the river Hellison the civic centre of the city of Megalopolis included municipal buildings grouped around a square agora ('marketplace'). There is no information at the archaeological site so it is difficult to interpret the ruins - maybe this diagram will help. It is based on the writings of the Roman traveller, Pausanias who described a city already in ruins but littered with statues - one of which came from the Temple of Apollo at Bassae. Today the corn growing on the site hides a lot, but columns from colonnades are visible and the footprints of buildings are there if you look.
marketplace

"...in the north section, on the right as one looks down the river, the townsfolk have made their market-place. In it is an enclosure of stones and a sanctuary of Lycaean Zeus, with no entrance into it ...
There is before this enclosure a bronze image of Apollo worth seeing, in height twelve feet, brought from Phigalia as a contribution to the adornment of Megalopolis."
Pausanias
Description of Greece
Philippian Colonade Ancient city of Megalopolis