This former slaughterhouse and livestock market in Spain's capital is now a multipurpose arts center, which has housed galleries, stages, recording studios, offices and more since 2007.

Construction on the original complex started in 1908, and included a surrounding wall measuring over a mile long that still stands today. It served as a slaughterhouse until 1996.

During renovation, architects tried to preserve as much of the original structure as possible, adhering to a concept called reversibility -- that is, it could easily be converted back to a slaughterhouse.