Annapolis Rock is one of the most popular hikes along Maryland's portion of the Appalachian Trail, and for good reason. The hike is relatively easy, and the views are spectacular. The hike is about 5 miles total, out and back. For another great view, Black Rock is only 1 mile further along the Appalachian Trail, which would add another 2 miles roundtrip.
Because of its popularity, the best time to visit is earlier in the morning. If you hit it right, you will see the thru-AT hikers leaving as you walk in, and you will see the day hikers arriving as you walk out. Annapolis Rock serves as a campsite for AT thru hikers as well.
The easiest way to hike this is to park at the AT Trailhead in Myersville. You then follow the white blazes for about 2 miles before you veer left and follow the blue blazes to Annapolis Rock. After admiring the view at Annapolis Rock, hike up another mile to reach Black Rock. The fork for this stop is relatively easy to miss; make sure to keep an eye out for the little sign. There are no blazes marking this trail, either.