Like Sean Bean in National Treasure, you won’t find the booty of the Knights Templar in the basement of the Old North Church, but there is a crypt here with thousands of bodies dating back to the 18th century. This prominent stop on the Freedom Trail is rich in colonial and Revolutionary War history, most notably because the 191-foot steeple was where patriots hung two lanterns on the night of April 18, 1775, warning that British troops were setting out by sea to their fateful encounter with local militias at Lexington and Concord. A walk around the church, constructed in 1723 (making it Boston’s oldest house of worship), is a revelation in irony: While the building played a role in the start of the Revolutionary War, most of its Episcopal congregants remained loyal to King George. Chimes from the steeple still announce Sunday services, thanks to the Bellringers Guild, which is comprised of MIT students.