This summertime offshoot of the Abbe Museum in Bar Harbor is located at the Sieur de Monts Spring area inside Acadia National Park. This was the original museum location (built in 1928). It touches on the archaeology of Maine, the Wabanaki (the Native American people indigenous to the area), and the first European settlements on Mount Desert Island.
It's located about 2.5 miles south of Bar Harbor, off ME 3.