File:Lock 72 on C and O Canal from NPS.jpg

English: Lock 72. NPS Site says: Lock 72 is a standard cut stone lift lock similar to Lock 73. The lock was finished in 1840, and it is built of limestone. It is located 7 miles above Lock 71 and almost a mile below Lock 73. Bolt holes and one remaining bolt protruding from the coping indicate an addition of a heavy timber coping that was later removed. The frame timbers are the upper lock gates are in place with complete hardware. Some of the lower gate hardware remains. There is a 3" wide, 2 ½" deep continuous vertical slot for a drop gate located 22" up the upper extension wall from the edge of the upper lock gate pocket. The upper extension walls are 4' long and turn at about a 60 degree angle to become the upper wingwalls. The wingwalls are 14' long for the towpath, and 13' on the berm, which turns back to run for 6' with the lock. This becomes the entrance to the bypass flume. The lower extension walls are about 14' long, the splay at about 60 degrees to become wingwalls. The berm then makes another turn and runs perpendicular to the lock until the exit of the bypass flume. There is a modern footbridge located at mid-lock. A notch in a cap stone at the mid lock possibly indicates that it replaced an older footbridge.