Jimmy Fallon, Jon Hamm in background Jimmy Fallon, Jon Hamm in background

Visitors to New York City's Top of the Rock — the roof deck of 30 Rockefeller Center, which offers stunning views of the Manhattan skyline — were in for a treat recently, when Jimmy Fallon and Mad Men star Jon Hamm teamed up to photobomb the unsuspecting sightseers as part of a Tonight Show prank.

One of Fallon's Tonight Show crew members was stationed on the rooftop with a point-and-shoot camera and offered to take pictures of visitors, who were told the shots would be used on NBC's website. (They weren't.)

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As the groups and pairs were posing, Fallon and Hamm inserted themselves into the background of the photos, with antics that got more and more ridiculous as the day went on — including a Lady and the Tramp dramatization involving a hoagie.

Check out the hilarious stunt below: