Being trapped inside a leaky shipping container on a hot day would probably give a fair approximation of being in a sauna, but thankfully Canadian-based design studio Castor provides something a bit more refined with its Sauna Box. Starting with an 8 ft (2.4 m) square shipping container, it has added a fully-functional wood-burning sauna with a cedar interior and a solar panel to power the lights.

The Castor team created Sauna Box after one of its founders, Brian Richer, decided he wanted a sauna at his cabin retreat but "didn't want to drive up every weekend to build it." The company has sold around 10 units to date, with one rumored to have been bought by American painter and photographer Richard Prince.

Sauna Box costs US$41,000 to buy, which isn't exactly cheap. However, you do get an integrated iPod stereo, an electric guitar hook-up, a Castor stool, a magnetic truck light, and bronze antlers thrown in as standard. And, of course, the freedom to privately sweat it out in a small room ... which could just be priceless.

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