Is there a secret tunnel in Animal Crossing City Folk?

There is not secret room above the Marquee. I've searched and searched. Truth is, the people walking around in the city just say things to say things. It doesn't necessarily mean it's true. But sometimes after 8pm, the cones blocking the tunnel in the city will be set aside, and you can go to Resetti's Surveillance Center.

Other answer: There MIGHT be a room above the Marquee. There are many theories about how to get it, but one is to get the gold VIP card, see any show, then talk to the clerk to get access to the secret room. Might be true, but might not be.