When I got married, our first apartment didn't have room for a layout – but this Life Like "Electric Railroad system" fit under the bed nicely. I have the two extended panels, to make it a 4x6.
I don't remember a tunnel on these, although there may have been another version.
I modified mine to include some sidings into the center section (where a Christmas tree might go).
Lots of railroading fun on the cheap!