On sunny days, London's 'walkie talkie' building makes the sidewalk nice and toasty (and melts plastic bits on your car) with its south-facing concave glass wall: http://www.bbc.com/news/magazine-23944679
Not quite a solar furnace, though.
Not quite a solar furnace, though.
http://www.nbcnews.com/id/39403349/ns/travel-news/t/death-ra...
Actually hang on, is it the same architect??
https://en.m.wikipedia.org/wiki/Rafael_Viñoly
Maybe he's actually out to burn things on purpose... /s