Well that was pretty easy. Casey's redoubt was located almost directly across the street (Williamsburg Road, State Rt. 60) from my Masonic Lodge. Which ironically is at the corner of Williamsburg Road and Confederate Avenue. It's situated in an area called Sandston which is located between the intersections of Nine Mile Road and Williamsburg Road (The location of Seven Pines National Cemetery) and Richmond Airport. There is considerable commercial development on Williamsburg Road as well as subdivisions on both sides. So I doubt there remains much of it. This is the spot where Joe Johnston was wounded and in turn Lee took command of the ANV. Here's a link that I hope you will find interesting.

http://www.hmdb.org/marker.asp?marker=10595