If I didn't already have a real pool, I would totally do this on our farm (Or at least try)!
DIY Swimming Pool using 9 full size pallets and a very large medium duty tarp
DIY Swimming Pool: Cool and Fun
37 Ridiculously Awesome Things To Do In Your Backyard This Summer. Build a swimming pool out of bales of hay.
They have a big version of this at RTS every year.
A personal favorite from my Etsy shop https://www.etsy.com/listing/234626699/rustic-redneck-pool-rules
Amazing Uses For Old Pallets – 20 Pics
DIY Dumpster Pool: This DIY pool will blow you away!
Are you enjoying an inflatable swimming pool for the summer? Chances are you are not enjoying the dirt that collects at the bottom of it. Here is how to inexpensively build your own handheld pool vacuum that will make cleaning up dirt a breeze.
Hay bales + tarp + twine = Redneck Pool Party!