There is a skyscraper in Manhattan that doesn't have any windows

The former AT&T Long Lines Building at 33 Thomas Street is a 550 foot tall skyscraper in the Borough of Manhattan.

It stands on the east side of Church Street, between Thomas and Worth Streets, in the Civic Center neighborhood of New York City.

The building is an extreme example of the Brutalist architectural style, with no windows and a flat concrete slab facade. 

The building is a telephone exchange or wire center building which contains three major 4ESS switches used for interexchange, or long distance, telephony, two owned by AT&T and one owned by Verizon.

The building itself is somewhat dull and boring, and without windows it is a bit eerie looking.