Tiny Earthship at the Terra Perma eco-resort in Harrington, Quebec, Canada. It's basically a form of passive solar home that allows you to heat your home and keep it cool just by controlling the energy from the sun.
There's one main wall in this Earthship and it's built in a U-shape using recycled tires that are filled with earth and then they piled on a bunch of earth on so that the wall and that huge mound that they created form a thermal mass that can absorb energy from the sun and what that's meant to do is create an indoor temperature that's stable all year round.
Huge south facing windows that let the sun in during the winter and then an overhanging roof to block the sun during the summer.
This tiny earth ship has a lot of really interesting sustainable features and it's a beautiful structure.