Curvy, slightly creepy, and occasionally vertigo-inducing sandstone walls at Upper Antelope Canyon.
Six bucks to park in the lot, and another forty for a ride on the back of a pickup truck plus a guided tour that lasts an hour and a half. Crowded, rushed, claustrophobic — but worth it.
How much would it cost to create a 3-D map of the canyon and a flood simulation that allows you to see (1) how fast the water rises during a flash flood and (2) a time-lapse animation of how erosion will alter the shape of the canyon over the next hundred thousand years?
Not sure, but it would probably be worth it.