May or may not be a figment of your imagination
The Armadillo chair, designed by Baltasar Portillo of El Salvador, might not look like something that could realistically support the weight of a whole human. It mimics the bare-bones wire structures of virtual 3D polygons, stripped down to its edges with no surfaces in between. It could even be made out of yarn, an elaborate result from a game of cat's cradle. But it's not; it's constructed from powder-coated wrought iron, meaning that its thin lines hold up even when sat upon. I wouldn't be surprised if it's the lightest iron chair in history.
The strange-looking outdoor seat does provide the aesthetic advantage of only overlaying your view of whatever's behind it with subtle red lines. It's like sitting on nearly nothing, although I can't imagine its hard iron wires are as comfortable to plant yourself upon as air itself might be. The prominent use of negative space against straight lines creates a visual that's simultaneously grounded and weightless.
If you're into a bit of surrealism in your outdoor furniture selections, then the Armadillo might fit in nicely on your patio. There are only three in existence at present, though, so good luck getting your hands on one.