I always thought it would be cool to use old railroad tracks for
bikes. Hook up the wheels to one of the rails with some kind of rail conversion for the wheels and simply pedal, no reason to steer, you could look all around as you pedal and move your arms any which way.
That's slower than walking! Plus the hill doesn't look all that steep. Still, it'd be faster and less ridiculous-looking to walk the bike up.
As for railcycling, that's very real. It does seem like alot of fun, though you'd have to be careful on abandoned tracks because sections go missing or misaligned often.