A road runs from the East River to the tip of the North Fork of Long Island, running through Long Island City, Woodside, Jackson Heights, Flushing, Auburndale, Bayside, Douglaston, Little Neck, Great Neck, Munsey Park, Port Washington, Muttontown, East Norwich, Oyster Bay Cove, Cold Spring Harbor, Huntington, Northport, Smithtown, Stony Brook, St. James, Port Jefferson, Rocky Point, East Shoreham, Wading River, Calverton, Riverhead, Aquebogue, Jamesport, Mattituck, Cutchogue, Southold, Greenport, Orient and Orient Point, and would go further were an ocean not in the way. It is a precolonial trace used by Native Americans before Verrazano and the Dutchmen who followed him caught sight of the lengthy island along whose north shore it limns. It’s Jackson Avenue, North Hempstead Turnpike, Lawrence Hill Road, Fort Salonga Road, North Country Road, Main Road, Route 25A, Route 25, and in NYC and Nassau County, it’s Northern Boulevard.
In Queens, Northern Boulevard has been called Jackson Avenue (the stretch west of Queens Plaza still is), Bridge Street, and Broadway; a Flushing enclave and LIRR station still bear the name Broadway after the old road. I’m unsure when the whole kaboodle was renamed Northern Boulevard; perhaps it was in the great 1920s “boulevard”-naming craze the Queens Topological Bureau underwent, when the Philadelphia-style numbering system was instituted and most major roads like Vernon Avenue, New York Avenue, and Rockaway Plank Road were given “boulevard” monikers.
To walk Northern Boulevard, or Routes 25A/25 from shore to shore would require a few days, and at the sluggish pace I generally employ, more than a week.