2. Hidden House in Lower Silesia, Poland
Located in Lower Silesia, this home is designed to be completely invisible from most angles. The Silesian language has fallen into hard times in Lower Silesia after the population saw almost total replacement during and immediately after World War II, and today most of the area speaks mainstream Polish (the argument as to whether Silesian is a separate language or a Polish dialect rages on).
The Hidden House is designed so that only the homeowner has access to the beautiful grassy roof area. Unlike a lot of underground homes, the Hidden House has some windows on the lower area that do let in some sun.