There’s a decent chance you’ve never heard of the mountainous Spanish region of Matarranya, which borders Catalonia and Valencia. But you might want to pack your bags—or, hell, even sell your place and head to the spot that some call the Tuscany of Spain. That’s because the area is increasingly becoming a hotbed for stunning, and stunningly weird, architectural experimentation.

Credit the boom to French developer Christian Bourdais, who has tasked up-and-coming architects from all over the world to fill the beautiful Matarranya, which is still largely untapped, with unconventional personal hotels called “solo houses.” Designboom has a gallery of some of the project’s coolest houses, including a summer retreat from Johnston Marklee and a circular marvel from office KGDVS. The newest studio to set up shop in the region is TNA, a Tokyo-based architectural firm that just might have the boldest idea for a solo house yet.

The architects unveiled their proposal for an upside-down concrete pyramid that’s partially submerged into Matarranya’s natural terrain. Since pyramids normally don’t have windows, TNA’s structure calls for huge apertures that let in light and provide ventilation.

Because the house is built on a slope, you enter from the middle level that overlooks the dining area below. Once you’re inside, you can move via passageways and Escher-like staircases between the four rooms, all of which are connected to the adjacent outdoor pool. Needless to say, it’s positively bonkers, and the kind of place you’d come up with if your first-grade art teacher asked you to draw the most outlandish house you could think of, or if your college roommate gave you a piece of paper, some crayons, and a joint, and said, “Go.”

Check out more images of the upside-down pyramid house here. No word on when or if it’ll be available to buy, but damn, it would be enough to just see the marvelous thing in the flesh.