Fort de Chartres State Historic Site preserves the final of four successive French colonial fortifications near Prairie du Rocher, Illinois. Built in 1753 from stone, this fort replaced earlier wooden structures established beginning in 1720 and served as the primary French governmental and military center in Upper Louisiana until British forces occupied it in 1765. The substantial stone construction distinguishes it from its wooden predecessors and represents an important example of mid-18th-century French colonial architecture. Today the site features restored structures, educational events, and heritage demonstrations that interpret its significant role in colonial-era history.
