INTRODUCING the Manhattan Ventilation Building

Today, the answer to an often-asked neighborhood question -- what's that little building parked between No. 25 and the river? It photobombs many a picture of Tudor City. . .

Say hello to the Manhattan Ventilation Building, built in 1940 as part of the Queens-Midtown Tunnel project. Like its sister across the river, the Queens Ventilation Building, it's equipped with 23 mammoth fans that provide a complete air change in the tunnel every 90 seconds.

An octagonal structure with a vague art deco look, the Ventilation Building shares its lot with a playground. Both were constructed by Robert Moses, the city planner behind the Queens-Midtown Tunnel (as well as the FDR Drive, the First Ave. Underpass, and the Tudor City Bridge). The playground was named in Moses's honor in 1982.