Several previously unnumbered mounds have been located in Section 5. Just to the north of a line between Mounds 43 and 44 is an obvious mound in Section 5F that was missed by previous investigators. It is observable from the highway and on foot. It is indicated on the UWM Map by an elevation of 128.6 meters (421.9 feet) above sea level and is surrounded to the north by the 128-meter (419.9-foot) contour line, making its height only 0.6 meters (2 feet). This mound has been referred to by some Cahokia investigators as Mound 43A since it is nearest to that mound. Mounds 91, 43, and 44 surround what appears to be a plaza. Washington University crews made a surface collection of the area in 1971, and the presence of a plaza was confirmed by the absence of cultural debris.