hell yea man, this will totaly work. I was watching one of those ritchy rich house shows and some guy had a secret room undering his pool that was like a garage, he stored all his classic cars and inside the garage (underthepool) he had like skylights so you could see up threw the pool from inside the garage. Its all just money man, if you could dig two deep enough holes then you could get a storage container and seal it with tar whatever that shits called they protect concrete fondation cover the outside of it all make sure theres no leaks water tight, then throw it in your very bottom hole fill that hole in to the top of the storage container, then you have a room already in a hole under your hole for your pond ... you get me hahaha
i read this thread a bunch of times now been thinking about it aww shit i cant wait to have my huge piece of land i am going to try and find one with a mountian on it so i can put build my house into the side of the mountian and deep so from the out side it just looks like a little shack hahaha