The sizzling Therme Vals in Switzerland definitely has to be among the  most contemporary hotel-spas on the planet. Merging the goodness of natural thermal springs – the only ones in the area, with astonishing architecture, the hotel is scorching in every sense of the word. And the most interesting part is the interior. With natural stone for both the indoor and the outdoor pools, ambient lighting and great textures, architect Peter Zumthor managed to create an unrestrained illusion of walking into some sort of elegant caves. Definitely count us in for a quick dip. [via ArchDaily]