National Historic Landmark - Portland Observatory
has been designated a
National Historic Landmark
This site possesses national significance
in commemorating the history of the
United States of America.
The Observatory is the nation's only remaining maritime signal tower. It served as a communication station for Portland's bustling harbor brom 1807 to 1923, announcing the arrival of ships with a unique system of colorful signal flags.
National Historic Civil Engineering Landmark
Built 1807
One of the earliest marine signal stations in the United States, this tower is unique in its engineering design and construction and contributed to the prosperity of Portland harbor as a vital center of maritime commerce during the "Golden Age of Sail"
