Caves and caverns abound in Washington County! Quite a few are located on private property, but a number are publicly accessible. Several caves of various sizes are located along the C&O Canal between Shepherdstown and Williamsport, and Boonsboro is home to one commercially operated cavern, Crystal Grottoes. Here’s a quick rundown, so grab a strong flashlight and come do some exploring!
Howell Caves – Milepost 89
The Howell Caves are a series of caves located in the limestone cliffs that run along the towpath upriver of McMahon’s Mill (Milepost 88). Unfortunately, due to construction underway at the time of this writing, you will have to stay tuned for pictures and our first-hand account of these caves. We will update as soon as possible!
In the meantime, you can read about the Howell Caves on the Maryland Geological Survey’s website. Also, if you’d like to learn more about the construction project and the towpath detour in this area, head over to this NPS site.
Dam #4 Cave (also known as “Bear Cave”) – Milepost 83.3
In my opinion, this cave is the most exciting of the local C&O Canal caves. The entrance is large and quite enticing, and inside it’s deep! We dared to explore this cave one summer afternoon when we showed up well prepared with a strong flashlight, long pants, and sturdy shoes. The floor of the cave was very uneven and strewn with large rocks, so we had to watch our step carefully. We found that the passage winds its way back for a few hundred feet. During wetter periods when rain has been heavier and more frequent than usual, a stream flows from the opening of the cave and water pools in certain areas inside the cave. Creepy crawlies are definitely in residence here! We saw one snake, two salamanders, and a bunch of huge crickets inside. Bats are always a possibility too. Yikes!
Inside Dam #4 Cave 
Dam #4 Cave Salamander
Easiest access is walking downriver along the towpath from the parking lot at Dam #4.
Snyder’s Landing Caves – Milepost 75 – 76.5
The Snyder’s Landing Caves are another series of caves located in the cliffs above the towpath. These caves are sprinkled between milepost 75 and milepost 76.5. Begin to keep your eyes peeled for the entrances once you are about half a mile south of the Snyder’s Landing boat ramp.
Working your way down from Snyder’s Landing, the first cave you will come upon is a single entrance cave.
Snyder’s Landing Cave
(Single Entrance)
Snyder’s Landing Cave
(Single Entrance)
Shortly after passing Killiansburg Cave (discussed below) you will find a cave with three entrances. Two of the entrances are easily accessible. The third entrance is a smaller, window-like opening higher up on the cliff. Reports are that these three openings are all connected within the cave, but we did not attempt to confirm this as the passageways seem to narrow down to claustrophobic levels rather quickly.
A few other, potentially interesting openings can be spotted in the Snyder’s Landing area, but they are far less accessible than these.
Killiansburg Cave – Milepost 75.7
Killiansburg Cave is probably the most historically significant of the caves along the C&O Canal. It made its way to fame following the Civil War’s Battle of Antietam on September 17, 1862. That day, a number of Sharpsburg’s residents took shelter in this cave as tens of thousands of rounds of artillery flew through the air above their once quiet little town. Subsequently, the cave was depicted in the October 25th, 1862 issue of Frank Leslie’s Illustrated Newspaper in a work by artist Frances Henry Schell. In Schell’s rendition, the cave appears quite enormous and seems to be protecting a very large group of people.
In reality, although it does provide a fairly large, sheltered space, Killiansburg Cave is not a deep cave. In fact, it’s not much more than a large overhang and is significantly smaller than Schell’s illustration portrays. If it weren’t for its Civil War fame, I would easily lump it in with the other Snyder’s Landing caves. You will find it up on the hill, approximately 25 feet or so above the canal.
Killiansburg Cave
as seen from the C&O Canal Towpath
Killiansburg Cave
looking out from inside
Crystal Grottoes Caverns
Located in nearby Boonsboro, a tour of Crystal Grottoes Caverns is an excellent way to spend some time while you’re visiting the area.
Approaching their 100th anniversary, Crystal Grottoes opened to the public in 1922 and is Maryland’s only “show” cavern. It’s a relatively small cavern, but boasts more formations per square foot than any other cave known to man. The temperature inside the cave is a constant 54 degrees year-round, so it’s an especially refreshing stop on a hot summer day. You can even pack a lunch and enjoy a little picnic on one of their picnic tables by the stream out front. A tour of Crystal Grottoes is a unique and fun adventure for the whole family. Good for a rainy day too. Stop on by! (Bring cash.)