Located north of Birch Point looking out into Machias Bay, Fort O'Brien dates to the Revolutionary War and its first naval battle. A few weeks after the shots at Lexington and Concord were fired, the British ship Margaretta escorted a Machiasport shipowner, Ichabod Jones, to the fort to ensure he returned to Boston with lumber needed for the construction of barracks. The townspeople, led by Jeremiah O'Brien, retaliated and captured the Margaretta. A few weeks later the British sent reinforcements.

Job Burnham built this tavern on Main Street. It looks much like it did in 1770. It is two stories tall with a gambrel roof and central chimney. The tavern sits on a stone foundation overlooking the Machias River. Its yellow paint and clapboard siding are appropriate to the colonial era as are the small panes of glass in the windows and above the door. The gambrel roof is indented with small windows on the second story. The tavern was constructed seven years after the first settlers arrived in Machias and played a role in the American Revolution.

The Osgood Family House, located on Main Street south of Fryeburg's commercial center, is a two-story frame dwelling sheathed in clapboards with a hip roof. It sits on a granite block foundation and has a central six-panel door framed by sidelights and an elliptical louvered fan that is protected by a bracketed projecting cornice. The house has many notable exterior details including a thin cornice decorated with a molding of semi-circles along the top of the front facade. Built at the turn of the nineteenth century, local lore indicates it was built for Henry Young Brown Osgood.

The Brown House was constructed for Francis Brown, the namesake settler of Brownville and son of Moses Brown, a Newburyport, Massachusetts, man who purchased the forested tract of land on which Brownville now sits. Sent by his father to establish a lumber mill and oversee the growth of the town, Francis Brown undertook the construction of an impressive two-story timber frame house.

Located on State Street in Ellsworth, the Colonel Meltiah Jordan House, is a two-story Federal-style structure, one of the most detailed in the area. It has an octagonal shuttered cupola and a balustrade around the low hipped roof. The symmetrical front facade has a central door covered by a portico (or porch) and flanked by 6-panel sidelights. The house has an excellent example of a Palladian window on the east side and a three-part window above the portico.

Located on Fish Street north of Fryeburg center, the Benjamin Wiley House is two-and-a-half stories, sits on a granite foundation, and has a side-gabled roof and clapboard-sided exterior. The house has many Federal-style features including a central brick chimney and symmetrical facade. The centralized door is framed by simple pilasters, sidelights, and an entablature with a detailed fan in a keyed arch. Attached to the dwelling is a two-story ell that connects to a screened- in porch and barn. Many prominent citizens of Fryeburg have lived on the farmstead including the following.

The Squire Ignatius Haskell House, found along the northern end of a former mill pond, is an example of late-Georgian style architecture with later elements of the Greek Revival style added. The two-and-a-half story dwelling is a rectangular frame construction with clapboard siding and a prominent gambrel roof. It sits on a granite fieldstone foundation and has a central recessed entry accented with Doric entablature and pilasters. Haskell came to Deer Isle from Newburyport, Massachusetts, with his father, Mark, and brother, Solomon, in 1778.

The Martin Kinsley House, located on Main Street, is a two-story Federal-style dwelling with later Italianate-style bracketing under the roof eave. The centrally located door is topped by a fanlight and narrow triangular pediment. The house is one of Hampden's earliest surviving residences and was the home of the first Representative to the United States Congress from the district. Kinsley served as a major in the Massachusetts militia during the American Revolution.

The Libby-MacArthur House is a two-story gambrel-roofed wood frame structure sheathed in weatherboards with brick nogging between the exterior wall studs. The symmetrical facade features a central gabled entrance enclosed in a vestibule and shed roofed dormers on the lower pitch of the roof. It also has a substantial central brick chimney. The dwelling is significant as one of only a few early gambrel roofed buildings remaining in Maine. Philemon and Martha Libby obtained the 100 acre property in 1777.

The Portland Observatory has been a fixture in the Munjoy Hill neighborhood of Maine's largest city since its construction. This unique structure is the only maritime signal tower still standing in the United States, and is as a testament to the city's success in maritime trade.