The Cobble Hill Tunnel is an abandoned Long Island Rail Road (LIRR) tunnel beneath Atlantic Avenue in Brooklyn, New York City, running through the neighborhoods of Downtown Brooklyn and Cobble Hill. When open, it ran for about 2,517 feet (767 m) between Columbia Street and Boerum Place. It is the oldest railway tunnel beneath a city street in North America that was fully devoted to rail. It is also deemed the oldest subway tunnel in the world by the Guinness Book of World Records.

Atlantic Avenue is a major thoroughfare in the New York City boroughs of Brooklyn and Queens. It stretches from the Brooklyn waterfront on the East River all the way to Jamaica, Queens. Atlantic Avenue runs parallel to Fulton Street for much of its course through Brooklyn, where it serves as a border between the neighborhoods of Prospect Heights and Fort Greene and between Bedford-Stuyvesant and Crown Heights, and between Brooklyn Heights and Cobble Hill. This stretch of avenue is known for having a high rate of pedestrian fatalities and has been described as "the killing fields of the city."