There are no limits to the imagination — and that also applies to architects. Some come up with the most amazing ideas. It's hard to believe that anyone actually lives in these houses!
Architects don't just think in right angles. Sometimes they also want to test the boundaries of what is feasible. In Europe, you'll find some unusual examples of such pursuits, along the lines of: "Live in an unusual way."
A house does not necessarily have to be built with straight walls and a tiled roof. Some houses actually move as if they were leading a life of their own. Others are so small that the inhabitants can hardly stretch out. Whether snail shell or feed silo, in Europe one can obviously live everywhere.