Video: Here's a silly fun experiment to do the next time you're at the Hoover Dam: try and pour a bottle of water over the dam. Instead of flowing downward like water almost always does, the water actually flies up and flows upward because of the super strong draft.
The structure of the dam creates an upward draft that makes water actually defy gravity - instead of travelling downwards, it is carried upwards by the wind. You have to see it to believe it! We didn't know just how powerful it was until we experimented and poured water over the edge.