Fogonazos has a neat story about the largest drainhole in the world: a spillway at the Monticello Dam in northern California. Link
Fogonazos has a neat story about the largest drainhole in the world: a spillway at the Monticello Dam in northern California. Link
Now that I think of it, my neighbor's man made swimming pond operates on a similar, albeit many times smaller, principle.
Its been unusually wet over here (in Soggy Scotland) this year so I may have answered my own question.
Perhaps there is a subterranean continent which has also experienced the worst flooding in memory.
Could'nt you Americans with all your technology send a probe, with camera to investigate?