The short cut "un" stands for "united nude" its a brand founded by a dutch architect (!!) and a shoemaker from England.
My personal favorits are:
..."Frame" frome the Ultra Collection

...and "Haiku" from The Classics

The Shoes which my professor weard are called "Fold", they are part of "The Classics"..


If you want to see more of these gorgeous shoes check out there page http://www.unitednude.com/