Cummins Lakes in British Columbia, Canada, are two lakes fed by an upper waterfall and then connected by a waterfall in between them. Pretty darned kewl, I'd say (and I do).
The Richat Structure in the Sahara Desert of Mauritania is a nearly circular formation almost 50 kilometers in diameter (30 miles). It was once thought to be an impact crater, but is now thought by some to have been caused by uplifted rock sculpted by erosion. For those who care, it lies pretty close to 19.5 degrees latitude. Nevertheless, the Richat Structure remains a mystery.