The Lieutenant William F. Callahan Jr. Tunnel is one of four tunnels, and one of three road tunnels, beneath Boston Harbor in Boston, Massachusetts. It carries motor vehicles from the North End to Logan International Airport and Route 1A in East Boston. Ordinarily, this tunnel is only used to carry traffic out of the city, and with the completion of the Big Dig it only collects traffic from I-93 southbound and downtown Boston; northbound traffic uses the Ted Williams Tunnel. As of 2016, a toll of $1.50 is charged for non-commercial two-axle vehicles with a Massachusetts E-ZPass, while non-Massachusetts E-ZPass holders are charged $1.75. Vehicles without E-ZPass are charged $2.05 through MassDOT's Pay By Plate MA program. For residents of certain Boston ZIP codes, a discount is in effect using an E-ZPass transponder, costing $0.20.

The North End is a neighborhood of Boston, Massachusetts, United States. It has the distinction of being the city's oldest residential community, which has been inhabited since it was colonized in the 1630s. It is only 0.36 square miles (0.93 km2), yet the neighborhood has nearly one hundred establishments and a variety of tourist attractions. It is known for its Italian American population and Italian restaurants.