Constantin Brodzki, CBR Headquarters, Brussels, 1970

This Brutalist gem is the work of the Belgian architect Constantin Brodzki, and was originally designed as the headquarters for the Brussels-based cement company CBR. Fifty years on and the modernist office building—now a co-working space for a lucky few—still packs a fantastically futuristic punch, thanks to its monolithic, modular façade of curved concrete and reflective glass.