The Boros Collection is a private collection of contemporary art. It contains groups of works by international artists dating from 1990 to the present. Different facets of the collection have been on public display since 2008 in a converted bunker, situated in Berlin-Mitte, with 3000 sqm of exhibition space spread over 80 rooms. The Bunker in constructed as an air raid shelter in 1943 by Nazis. Christian Boros purchased the bunker for his private collection in 2003. He had architects Jens Casper and Petra Petersson convert the building into a 3,000 m2 exhibition space. The collection features 130 works by 23 artists, including Ai Wei Wei, Olafur Eliasson, Thomas Ruff.