If you have boys the chances are that you have a train set. The only trouble is that once the bug hits it can get very expensive. A and B are always piling up things to make bridges etc. to go over the basic track; and they usually fall down within 30 seconds (cue the temper tantrum!).
Having got fed up with rebuilding every circuit of the track when the boys played with the trains I decided to get them a tunnel. This is when I discovered how much these things are (yes it does really say 34 and a half dollars!) for a plain arch glued to a piece of track.
So having had a scout around the house here is our version
Yep it is a washing detergent bottle that was destined for the bin that has been cut to shape. I love a freebie!