Blockhouse No. 1

Blockhouse No. 1, colloquially known as The Blockhouse, is a small fort in the North Woods section of Central Park, Manhattan, New York City. Finished in 1814, the Blockhouse is the second-oldest structure in the park, after Cleopatra's Needle, and the oldest surviving structure originally built within the park site. It is located on an overlook of Manhattan schist, with a clear view of the flat surrounding areas north of Central Park.

The fort was part of a series of fortifications in northern Manhattan, which originally also included three fortifications in Harlem Heights (now Morningside Heights). It was accompanied by Blockhouses No. 2, 3, and 4 in Morningside Park. The fort is the last remaining fortification from these defenses. Frederick Law Olmsted and Calvert Vaux, the designers of Central Park, treated Blockhouse No. 1 as a picturesque ruin, romantically overrun with vines and Alpine shrubbery.