According to Beautiful Life:
A young couple with two children from Mexico City who after living in a conventional home wanted to change to one integrated to nature. The goal of this project was to make it feel like an internal inhabitant of a snail, like a mollusk moving from one chamber to another, like a symbiotic dweller of a huge fossil maternal cloister.
You can see more photos, including the original plans for the house, at Beautiful Life. I have no idea if the house is for sale or the owners are just showing it off, but either way I'm happy someone put it online so we could all bask in its splendor. So let's all put on the soundtrack from The Little Mermaid, click this link, and float around singing along.