Merzbarn website - Schwitters
An interesting, and recently done site devoted to the final Merzbau project of artist Schwitters, unfinished Merzbarn in Cumbria:
http://www.merzbarn.net/
there is also a wonderful Dutch site on the barn project - with detailed photographs and outline of the work.
in the above video clip, from a generously posted series, is Max Ernst and toward the beginning, short footage of the Merzbarn, and Schwitters during the war.