This site is dedicated to waterfalls, mountains, an old aviators memories, with lots of poetic liberties, some just plain made up, and interesting places to visit.
Rock Island should probably be listed under odd stuff.
When a dam was built on a "U" turn in the river and the water backed up, due to limestone between the curves that form the "U" water started to seep through to emerge in the wall of the now lower river.
The following photos are the results. Note the water comes out of the cliff.