Cahokia is a small town with a large history. The French colonial relics — the courthouse, the log church — are among the oldest surviving structures in the Mississippi Valley and require only a short visit, but they reward attention. The nearby Cahokia Mounds, the pre-Columbian city that gave this region its name, is a different and larger experience entirely, and can be combined in a half-day excursion from either Cahokia or St. Louis.