We recently stopped at Interstate Park which is on the border between Minnesota and Wisconsin. It is a wonderful park and home to the largest concentration of Glacial Potholes in the world. The glacial potholes form when rocks in a fast moving river fall into a small divot and swirl around knocking against the rock and acting as a drill. They make circular drill holes some times called “Witches’ Cauldrons”. Often quite small, some in the park are over 60 feet deep!

Crystal, Kai and Nora at Interstate Park checking out the glacial potholes. In both quantity and size of potholes it is a world wonder.
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Ben, Kai and Nora pose on the edge of cliff in the park.

Kai and Nora climbing on rocks in the park.

An HDR shot of the Taylors Falls Queen

Checking out one of the larger cauldrons. Kai is maveling at the duckweed growing in the hole. Duckweed is, of course, the world's smallest flowering plant.

Nora and Crystal check out a pothole in this HDR pic

Getting ready to decend into the "Bottomless Pit". It turned out that it did have a bottom but at over 60 feer deep it was an impressive glacial pothole.

Getting ready to decend into the "Bottomless Pit". It turned out that it did have a bottom but at over 60 feer deep it was an impressive glacial pothole.

Kai on a natural rock bridge
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Nora on a natural rock bridge

A view down one of the deeper ones.

An HDR shot of one of the larger glacial potholes