"In a hole in the ground there lived a hobbit. Not a nasty, dirty, wet hole, filled with the ends of worms and an oozy smell, nor yet a dry, bare, sandy hole with nothing in it to sit down on or to eat: it was a hobbit-hole and that meant comfort." –JRR Tolkien, The Hobbit
Take Bilbo Baggins's home. Add one part devastatingly cool German modernism and some super-canny sustainability tricks and you've got Villa K, a new home built into a German hillside by Dutch firm Paul de Ruiter Architects.
The main living space and the bedrooms, wrapped with floor-to-ceiling windows, face south — better to catch the sun. Less appealing spaces (e.g., the pantry, the "hunting room" and a six-car garage) have been burrowed into the mountainside, where rooms naturally maintain warmth and cut down on energy costs. Said setup also leaves more space on the south-facing side for a raised, U-shaped terrace and its pool, which appears to hover over the hill.
If you have a better way to spend an afternoon in Germany, we'd like to see it.