A National Historic Landmark, Fort Halifax Blockhouse was erected as part of Fort Halifax. The blockhouse is the oldest extant wooden blockhouse in the country and the only surviving element of the fort structure. It is built of hewed logs with dove-tailed and pegged joints. It is approximately 20' square and two stories high with an overhanging second story and a hipped roof. Located at the confluence of the Kennebec and Sebasticook Rivers, the fort was built by English settlers in 1754 to protect colonial settlements along the Kennebec.

The Lincoln House, located on Main Street, is likely the oldest surviving building in the town of Dennysville and dates from the first settlement of the area in the late eighteenth century. The side-gabled house sits on a mortared fieldstone foundation and is covered with clapboard siding. The structure is two stories with a central doorway topped with a triangular pediment. The home was built by master builder Joshua Chubbuck for Theodore Lincoln.

The Adams-Cate House, located in Castine, is a two-story Federal-style home notably known its curved interior hall with a curved door and staircase. The exterior of the house includes an elaborate elliptical fanlight and sidelights around the front entry that allows the maximum amount of light into the house during the long dark winter months. The original owners, Thomas and Jane Adams, built the house in 1815. Thomas was a businessman, selectman, and Representative to the General Court of Massachusetts. Their daughter, Jane Elizabeth Cate, also raised her family in the home.

The Alfred Shaker Historic District encompasses buildings from the eighteenth, nineteenth, and twentieth centuries. Located on Shaker Hill Road, the area is approximately 300 acres. It sits on a hillside and is bordered by stone walls and forested lands. Development of the area began in 1793 with the construction of a Meeting House. Soon after, several two-story dwellings, shops, and agricultural outbuildings dotted the landscape. There are twenty structures in total.

One of Portland's few surviving Federal period homes, the William Minott House is a three-story wood frame structure. Clad in flush tongue-and groove boards on the facade and clapboards on the other elevations, it has a low-pitched hipped roof with two chimneys on either end. The facade is symmetrical with a central entry door. The door is framed by sidelights and topped with an ornate elliptical fanlight. Above the door on the second floor is a three-part rectangular window.

The Blackhawk Putnam Tavern, a two-story house in the Federal style, overlooks the town of Houlton at the intersection of US Route 1 and US Route 2. Purportedly the oldest wood frame building in Aroostook County, it also features Greek Revival-style elements such as pilasters and an entablature. It's distinctive portico, or porch, was added in the early twentieth century. It was built in 1813 for Aaron Putnam by master carpenter Amos Wormwood of Alfred. Located near the Military Road (Route 2), which was completed in 1828, the house also operated as a tavern.

The First Church of Belfast demonstrates the influence of Asher Benjamin's design guides on early New England architecture. Architect Samuel French largely borrowed Benjamin's "Design for a Meeting House" for his work for the First Church of Belfast, which was constructed for a congregation founded in 1796. In addition to its stately Federal-style architecture, the church's most easily-recognizable features include its clock faces and its open belfry, complete with a Paul Revere bell.

The Captain James Morison House is an excellent example of a late Colonial era rural residence in inland Maine. The dwelling sits on a granite foundation, is two stories, and sheathed in clapboard siding. The facade is symmetrical with a central door topped with a bracketed hood (added later), and the gabled roof has two chimneys. Other structures on the property include a barn and shed. Captain Morison, a Revolutionary War veteran, joined the Continental Army soon after the siege on Boston.

Located between York Harbor and Cape Neddick, the Moody Homestead is a relatively modest, late Georgian-style two-story, side-gabled structure, sheathed in clapboards. The facade is symmetrical with a central entry. The entry door is framed by pilasters supporting a narrow cornice and topped by a narrow transom. Each end of the building has a one-story projecting vestibule, the south facing containing a secondary entry door. The second floor windows are slightly shorter than those on the first floor and sit just below the eaves.

Designated a National Historic Landmark, the McIntire Garrison is one of the most notable examples of a garrison remaining in Maine. Located just north of the York River in rural York County, the McIntire Garrison is a two-story side-gabled log building with an overhanging second story and a central brick chimney. The building has wood clapboard siding on the long sides and wood shingles on the ends. A central entry is located on the south elevation facing the river, which provided the primary means of transportation at its time of construction.