The Old Belfry is a wooden bell tower on a small hill just off the Battle Green — the bell that rang the alarm on the morning of April 19, 1775, calling the Lexington Minutemen to muster. The current structure is a replica (the original fell down in the 19th century), but it stands on the original site and still rings on Patriots' Day.
It is a small monument, easy to miss amid the more prominent Battle Green and tavern museums, but worth the two-minute detour. The hill gives a slightly elevated view over the Battle Green and surrounding streets.