Roachtown topographic map

To the south of Monks Mound is the Grand Plaza, a large area that covered roughly 50 acres (20 ha) and measured over 1,600 ft (490 m) in length by over 900 ft (270 m) in width. Researchers originally thought the flat, open terrain in this area reflected Cahokia's location on the Mississippi's alluvial flood…

Average elevation: 128 m

Average elevation: 127 m

Average elevation: 127 m

Average elevation: 129 m

Average elevation: 182 m

Average elevation: 125 m

Average elevation: 126 m

Average elevation: 124 m

Average elevation: 123 m

Average elevation: 134 m

Average elevation: 174 m

Average elevation: 157 m

Average elevation: 135 m

Average elevation: 138 m

Average elevation: 128 m