Were the Portsmouth Earthworks a Portal to the Path of Souls?

My quest to understand the enigmatic Portsmouth, Ohio earthworks began in the 1980s. The site is an almost indescribable series of geometric earthwork formations and mounds connected by graded and earth-enclosed linear walkways. The walkways were a uniform 160-feet wide and were outlined on their sides by walls of earth 3-5 feet in height. The walkways extended for nearly 14 miles. What appears to be the central feature of the massive site was a set of two large, horseshoe-shaped earthworks made from walls of earth some 12-feet high. The map with this feature shows it labeled "A." The horseshoe embankments were enclosed by a circular wall of earth with several mounds and other linear features in the immediate area. One of these horseshoe embankments remains today and it is located in a park on a high hill in Portsmouth. If modern buildings encircling this site were not present, an expansive view of the entire Portsmouth complex, which extends across the Ohio River into Kentucky, would be possible.