In 1953, NYC retired its pneumatic tube-aided mail system, which stretched 27 miles long and connected 23 post offices. But there are still remnants of the obsolete technology scattered throughout the city.

Tubes in the old Chelsea post office
Naturally, the old Chelsea post office, which is being sold by the United States Postal Service, was once a hub of pneumatic activity. And the tubes are still visible, according to Untapped Cities.
Another place to spot the old tube system is at the main branch of the New York Public Library, which still used pneumatic tubes until relatively recently. Several years back, paper requests for books in the stacks of the Humanities and Social Sciences library were sent down via pneumatic tubes.

Trash tubs on Roosevelt Island
And finally, one of the most unique pneumatic tube systems still in use today has to be Roosevelt Island’s AVAC (Automated Vacuum Collection) trash removal system.
“AVAC connects all the buildings on [Roosevelt] Island with a series of high-speed pneumatic tubes, which forces trash to fly under resident’s feet at 50 MPH,” NYC-Grid writes. The AVAC system moves 5.8 tons of trash per day, according to Untapped Cities. – Christopher Cameron