structural:scholar_edition, information:extraction, structural:summarization
Urban landscape

Early in its history, Cahokia underwent a massive construction boom. Along with the early phase of Monks Mound, an overarching urban layout was established at the site. It was built with a symbolic quadripartite worldview and oriented toward the four cardinal directions with the main east–west and north–south axes defined with Monks Mound near its center point. Four large plazas were established to the east, west, north, and south of Monks Mound.

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 plain, but instead soil studies have shown that the landscape was originally undulating ridge and swale topography. In one of the earliest large-scale construction projects, the site had been expertly and deliberately leveled and filled by the city's inhabitants. It is part of the sophisticated engineering displayed throughout the site. It was used for large ceremonies and gatherings, as well as for ritual games, such as chunkey. The game was played by rolling a disc-shaped chunky stone across the field. The players would throw spears where they thought the chunky stone would land. The game required a great deal of judgment and aim.

The major ceremonial north–south 'axis' connects the main precinct with the large ridgetop mortuary mound to its south now known as the Rattlesnake Mound (Mound 66). The feature, named the Rattlesnake Causeway by archaeologists, was an elevated embankment about 18 metres (59 ft) wide, roughly 800 metres (2,600 ft) in length and varies in height from 0.5 metres (1.6 ft) to almost 1.3 metres (4.3 ft) as it traverses a low swampy area to the south of the Grand Plaza. It is aligned 5° east of north, a direction thought to mimic the maximum southern moon rise of 5° west of north, albeit in reverse. This is thought to have had symbolic associations to the builders in connection with their lunar maize goddess of the underworld. This is further strengthened by its close proximity to the ridgetop mortuary Mound 72, the underworld connotations of the low water-filled area the causeway traversed, and its terminus at the mortuary complex at the Rattlesnake Mound. The causeway itself may have been seen as a symbolic "Path of Souls".

The high-status central district of Cahokia was surrounded by a 2-mi-long palisade that was equipped with protective bastions. A later addition to the site, when the palisade was constructed, it cut through and separated some pre-existing neighborhoods. Archaeologists found evidence of the stockade during excavation of the area and indications that it was rebuilt several times. Its bastions showed that it was mainly built for defensive purposes.

Beyond Monks Mound, as many as 120 more mounds stood at varying distances from the city center. To date, 109 mounds have been located, 68 of which are in the park area. The mounds are divided into three different types: platform, conical, and ridge -top. Each appeared to have had its own meaning and function. In general terms, the city center seems to have been laid out in a diamond-shaped pattern about 1 mi (1.6 km) from end to end, while the entire city is 5 mi (8.0 km) across from east to west.