It was wedged in a narrow, inaccessible space between two buildings, about three blocks from the World Trade Center site. And there it remained, hidden from view, for more than 11 years. Ground zero slowly gave way to a new tower. Protesters gathered nearby, angry over a planned Islamic center.

But this week, land surveyors happened upon it — a piece of a plane’s landing gear, apparently belonging to one of the two jets that slammed into the twin towers on Sept. 11, 2001, the police said.

On Wednesday, around 11 a.m., the surveyors called 911 to say they had found a piece of damaged machinery. What the police discovered was a component about 5 feet high, 3 feet wide and about 17 inches in depth. It was lodged in the narrow gap between 50 Murray Street, a residential building, and 51 Park Place, which is empty. There, it had been “out of sight and out of mind for over a decade,” the Police Department’s chief spokesman, Paul J. Browne, said on Friday.