I love tight-rope ideas - so here's another one. (I have more)
Standing Wave Tight-rope spans a valley and displays standing waves.
In the off position, it's just an ordinary tight-rope, but when the vibrator is activated at the anchor point on one side, the wire displays the characteristic nodes
and anti-nodes of a standing wave.
Illuminated at night, probably using strobes, Standing Wave Tight-Rope becomes a visitor attraction spectacle.
(Standing Wave Tight-Rope is not recommended for walking on when in the "activated" mode)
see links for more information on vibrating strings and wires.