We've long been supporters of underground tourism. A 60-minute guided tour through a cool, dark cave on a sweltering summer afternoon is a great way to recharge the let's-drive-until-sundown batteries. Commercial caves, however, have encountered declining attendance in recent years. Owners have been forced to come up with inventive extras to keep the tourists coming.

The latest entry in this can-you-top-this sweepstakes is California's Moaning Cavern, which plans to string the world's longest zip line through the hillsides above its hole. The line will reportedly be 1.5 miles long, and the ride will take over 90 seconds at speeds of over 60 mph. The owner claims to have gotten the idea from watching a silent film stunt performed by Tom Mix.

The precise trajectory of the line isn't clear from news reports, but we hope that it starts at the parking lot and ends inside the cave at the top of their 100 ft. spiral staircase.

[02/02/2008]