The Observer Building is a historic commercial and residential building located at 128 Union Square in Dover-Foxcroft, Maine. Built in 1854, it is an architecturally unusual Greek Revival wood-frame "flatiron" triangular building with a variable-pitch gable roof. In addition to its architectural significance, it is also historically significant as the home for many ye…The Observer Building is a historic commercial and residential building located at 128 Union Square in Dover-Foxcroft, Maine. Built in 1854, it is an architecturally unusual Greek Revival wood-frame "flatiron" triangular building with a variable-pitch gable roof. In addition to its architectural significance, it is also historically significant as the home for many years of The Piscataquis Observer, one of Maine's oldest weekly newspapers. The building is now owned by the Dover-Foxcroft Historical Society, which uses it as a museum and storage space.