Old Ironsides is turning 221.
A Saturday celebration at the Charlestown Navy Yard in Boston is marking the Oct. 21, 1797 birthday of the USS Constitution, which is the world's oldest commissioned warship still afloat.
The festivities will also mark the birthday of the U.S. Navy on Oct. 13, 1775 as well as the Dec. 31, 1943 birthday of the USS Cassin Young, a World War II-era destroyer that's also docked at the Navy yard.
Naval drills, rope and knot making demonstrations and a scavenger hunt are among the free activities scheduled.
The USS Constitution was built in Boston as one of the nation's original warships.
It earned its nickname "Old Ironsides" during the War of 1812 and its current crew members are all active duty sailors.