(Photo: Getty Images)

The basics:
The city's celebration is older than the country itself, dating back to 1762. Strictly marchers only (no cars or floats allowed), this year's 248th annual parade is led by the Fighting 69th Infantry of the New York Army National Guard. The festivities begin with a blessing from Cardinal Edward M. Egan, archbishop of New York, who will celebrate Mass at St. Patrick's Cathedral at 8:30 a.m.—not long before crowds start gathering along the parade route.
• Tuesday, March 17, 11 a.m. to approximately 5:30 p.m.
• The parade begins at 44th Street and Fifth Avenue and proceeds north along Fifth Avenue to 86th Street.
• Free

The best vantage points:
• Any spot along Fifth Avenue toward the north end of the parade route, far from the midtown crowds and NBC camera crews.
• The steps of the Metropolitan Museum of Art (1000 Fifth Ave., at 82nd St.) are a good bet, since marchers often pause outside the nearby American Irish Historical Society.
• The official viewing stand lies at 64th Street, and free tickets are available for bleachers running from 62nd to 65th Streets. Seating is on a first-come, first-served basis. Call 718-231-4400.

The participants:
• Cardinal Egan officially reviews the parade and greets crowds from the steps of St. Patrick's Cathedral.
• Mayor Bloomberg marches along with a crop of local politicians.
• Michael J. Gibbons, president of the Ireland-U.S. Council, is this year’s grand marshal, with the 69th Regiment acting as his military escort.
• Niall Burgess, counsel general of the Consulate General of Ireland.
• Royal Canadian Mounted Police, as well as members of the NYPD.
• Fire Department commissioner Nicholas Scoppetta marches with other FDNY members.
• Bagpipe bands hail from Finland; Brittany, France; Spain's Gallaica region; and, of course, Ireland.
• High-school bands from across the country.

The television coverage:
• Armchair spectators can tune in to NBC (Channel 4), which will be taping live from 11 a.m. to 3 p.m. at various points along the parade route.