Admission to the historic Portland Observatory on Congress Street will be free on Friday (June 14) in honor of Flag Day.

Greater Portland Landmarks, which operates the Portland Observatory, will offer tours of the Munjoy Hill landmark between 10 a.m. and 5 p.m. along with craft activities for children, live music, and guided walking tours of Munjoy Hill and the nearby Eastern Cemetery.

The property is a National Historic Landmark and represents the last remaining maritime signal tower in the United States. The 86-foot-tall tower, which was built in 1807 by Capt. Lemuel Moody, enabled Moody to alert merchants and ship owners that a ship was arriving in port.

The city of Portland took ownership of the Portland Observatory in 1937. It is open from Memorial Day weekend through Columbus Day.

According to its website, there are 103 steps between the street level entrance and the Observatory’s lantern deck.

Flag Day is celebrated June 14 to honor the day in 1977 when the Second Continental Congress adopted the U.S. flag.