Where can i get a tunnel?

Any websites to get them?

If the tunnel is not going to be used as a portable unit. Building your own onto your layout is just too easy. Buy some tunnel portals. And go from there.

I don't know what the current most popular tunnel building method is, but hydrocal with stripes of newspaper was more like playing than working. I felt like I was re-living my kindergarten years. So did my wife. Hydrocal powder in what seemed like everywhere, or so my wife said. But was it ever a blast!!

I agree with Terry. Any commercially-made tunnel/mountain big enough to be reasonably realistic (i.e., longer than the train going through it) would be too big to stock or ship as a practical matter.

Making one is fun and easy. Go for it!

For o gauge mth and some foam ones are your commercial choices. Most are made by the Modeler.