In recent months, there's been a lot of debate over whether architects should design prisons, a discussion that hit a peak when the American Institute of Architects ruled earlier this year that its members should not refuse to design the controversial structures. Compared to the thorny ethics of building prisons, the task of converting them seems like a wholly positive one. What can be more rewarding and intriguing than turning hubs of incarceration and execution into productive new spaces? The U.S. has no shortage of empty prisons begging to be rehabilitated, and there are a few ambitious visions in the works already (a movie studio! Condos! A sustainable farm!). While those projects get underway, take a look at how other prisons around the world have been transformed in the last few years.