Brodhead Armory. Built in 1930, designed by William Buck Stratton, with priceless W.P.A. art on the interior, and glazed exterior tile work by Buck Strattons wife, Mary Chase Perry – founder of Pewabic Pottery.
Now closed and awaiting total destruction.
I wouldnt exactly call this building “wide open”, but it certainly has been breached after its official closing, as shown here.
[detroitfunk adds: Here is a photo from the post I did years ago on the last open day of the Armory – notice the pristine condition of the parkay flooring]