Am I CRAZY?
Where my old home once stood now lies a big square open hole in the ground.
The 30' X 40' area is about 6ft. deep, poured concrete floor. Some walls are poured concrete with one of concrete block. It's a very safe distance from the new replacement home.
I would like to fill it with water to use as a Natural "Swimming" Hole or transform it to a useful water feature.

Is this a feasible or workable idea? Do you know of someone who has? What do I need to do without dropping in a liner and spending a fortune?

Any experienced ideas would be most gratefully appreciated.
Thank you folks.