Partway down North Carolina's Patsy Pond Nature Trail is a small pond that looks like it might be a nice swimming hole until you see the plaque identifying the water as Bob's Sinkhole. 

Formed in 2003 as the result of a cover-collapse formation, where a thin layer of clay finally fell into a water table hidden below the surface, the small indentation in the land seems almost too insignificant to be charted. Enter wildfire technician Robert "Bob" Kaylor who discovered the sinkhole while working in the surrounding Croatan National Forest. Suddenly the little sinkhole which would otherwise have gone unnoticed, and possibly dangerously so, had a humble name all its own. Casual hikers can still visit the sinkhole and be thankful that all geography is not named so simply lest we live in a world surrounded by Mount Norm and Theresa's Ocean.  

Update: As of December 27, 2016, the plaque is no longer there, but do not despair. Bob's Sinkhole is very easy to find as it is about 50 feet west of the trail head, just start walking down the main trail, look to the right, and there's Bob's Sinkhole.