The South Campus trails is a network of mountain biking (and hiking) trails on land owned by the University of Mississippi in Oxford, Mississippi. The trails are accessible from a few places, but are most often accessed from Chucky Mullins Drive near Highway 6. These trails connect at various places to the 2.5-mile South Campus Rail Trail (formerly/also known as the Thacker Mountain Rail Trail and Whirlpool Trail), which was formerly part of the Mississippi Central/Illinois Central Railroad.
There are no published figures about the total length of the trail network, but I think the total easily eclipses 20 miles. The Ole Miss Campus Recreation website has several embedded/linked maps, but none of them are the same or totally accurate. As of this writing, OpenStreetMap (shown below), has all the trails correctly mapped.
The trails are designed and constructed primarily for mountain bikes (though I've rarely ever seen a bike there) and are largely very circuitous. The goal of the system system seems to be to provide as much trail system mileage as possible in a small area, which is fine for providing recreation opportunities close to town. The vast majority of the trail system traverses small forested hills, but one trail does follow a power line corridor. There are two larger ponds, and one smaller one, as well as several ephemeral streams. Remnants of previous settlements are also encountered along some of the trails, including a gravesite, barn, old roads, and former dam.
For the most part the trails are poorly marked and there's no way to distinguish one trail from another. This is especially problematic because sometimes several trails converge at the same place and there can be unofficial trails connecting the official trails. There are places where trees have blazes to help find your way, but these are typically in one direction and are by no means consistent. And of course this is all made worse by the maps on the Ole Miss website that are inconsistent with each other and wrong. Using these trails takes either as sense of adventure or prior knowledge gained from using the trails.
There are more photos of these trails in this album of mine.