"THE MURDER OF SHERLOCK HOLMES"
In the pilot for the long-running mystery series, the major location which could only be found in Toobworld was New Holvang, New York, outside of the City to the north, probably about an hour away. But on a more trivial level there was the Serendipity Theatre on the corner of 3rd Avenue and 17th Street.
Based on the shape of the theater building on the street corner as seen in the episode, I think the theater would have to be this one in the real world:
What with filming always happening on the streets of Manhattan, this street corner may have already appeared on TV screens as it looks here. If so, then it's now locked into place in Toobworld as well. Not a problem, as in the time since the episode was first broadcast, the theater could have been reconverted back to this storefront.
Across the street, the corner looks like this:
It looks like a building must have been taken down there in the last thirty years to put up that newer edifice with more public space. So the theater could have been there as well. In Toobworld, of course. I'm not so far gone that I think the Serendipity Theatre actually existed in the real world!