Whale's Jaw Trail is a 2.5-mile loop trail located in the historic area of Dogtown. The trail offers views of the woods, boulders, and the remains of an old settlement. The trail is named after a large boulder that resembles a whale's jaw, which was split by a blast of dynamite in 1989. 

Dogtown is a historical settlement in Rockport that was abandoned in the early 19th century. It is now a wooded area with trails and ruins of old houses and cellars. Dogtown was originally settled by farmers and commercial anglers in the 17th century, but after the War of 1812, many residents moved to the more prosperous coastal villages. The remaining inhabitants were mostly widows, vagrants, and outcasts, who kept dogs for protection and companionship. The area became known as Dogtown, and was reputed to be a haven for witches and pirates. By the 1840s, Dogtown was completely deserted, and nature reclaimed the land. Today, Dogtown is a popular destination for hikers, bikers, and history buffs, who can explore the remnants of the past and enjoy the scenic views of the Cape Ann peninsula.

The AllTrails website has a map and description of the Whale's Jaw Trail.