Getting there: The Grayson family vault is about two driving miles east of I-95 and one mile west of U.S. Route 1 off the Prince William Parkway (VA Rte. 294) in Woodbridge, Va. From Rte. 294 turn southwest onto W. Longview Drive. Proceed five blocks past Matthews Drive and Grayson Road, then turn left into the driveway at the historical marker. A small lot on the left is reserved for visitors, from which a walkway leads to the tomb. Please do not proceed further up the driveway, as this is private property.