art-agenda has a thematic examination of gallery spaces online every two months, with the current feature being underground spaces.
Not so underground… Vienna Sezesion CC-NC 2014 Rob Shields
Barbara Sirieix notes that underground galleries include purpose built spaces such as the Städel Museum in Frankfurt as well as parking garages and appropriated and converted basement spaces where many artists also work because of economic considerations. These spaces often become part of artworks and installations.
-Rob Shields (University of Alberta)