Portland Observatory

Portland Observatory, built in 1807 on Munjoy Hill in Portland, Maine, is the only known surviving maritime signal tower of its kind in the United States. Organized by Captain Lemuel Moody, it let merchants learn of arriving ships before they reached the docks by using a telescope and signal flags to communicate between ship and shore. It also served as a watch tower during the War of 1812. The 86-foot octagonal tower remained in practical use until 1923, when radio and engine-powered vessels made it obsolete. Restored over time, it is now preserved as a museum and recognized as a National Historic Landmark.

Portland, Maine · United States