The Sewers of New York City are the location in New York City where the Turtles' lair is normally located. They live there due to their sensei, Splinter, who either lived there before their mutation or retreated into the sewers following the transformation of both himself and the Ninja Turtles. In both the 2003 and 2012 series, the turtles' hideout is close to a subway line.
- The "Sewers of New York City" featured in most incarnations of TMNT are actually more similar to New York City's system of storm drains. In real life, they are not usually suited for permanent underground human habitation because they regularly flood with water when it rains.