From a distance Refugi Lieptgas looks like a traditional wooden hut. Taking a closer look you will actually find that this cabin is made of concrete.

http://homeworlddesign.com/refugi-lieptgas-concrete-cabin-in-the-swiss-alps/

Refugi Lieptgas is a fascinating concrete cabin designed by German architecture studio Nickisch Sano Walder Architekten. Refugi Lieptgas is situated in Flims, in the Swiss Alps, it is entirely built of concrete and has an area of 40 sqm. From the architect: From a distance Refugi Lieptgas looks like a traditional wooden hut.