On Friday night’s Late Night with Jimmy Fallon, Fallon showed audiences how NBC crews had constructed an exact replica of his set next door in Studio 6A, where the show will air when it returns from this break until February 2014.

That’s when Studio 6B (where Fallon had taped for the past few years) will be completely overhauled for his debut as host of The Tonight Show.

For perfect symmetry…

Studio 6A was the home for Late Night from 1982-2009 for both David Letterman and Conan O’Brien.

Studio 6B was the home for The Tonight Show from 1957-1972 for Jack Paar and Johnny Carson, before Carson took the show west to Hollywood and Burbank.

Fallon effectively closes the loop on both.

Roll the clip.