Culvert 241 at 182.63 miles on the Chesapeake and Ohio Canal. The NPS site says:This culvert has a semi-circular arch that spans 4', and it carries water beneath the canal. The outflow face is filled to a course under the coping. The inflow side is a concrete drop inlet with a flat, square opening 9' wide by 72' wide. A 15 steel pipe with a steel gate and concrete curb takes water out of the canal to the river. The opening is full of debris.