Sports stadiums. There should never be a single dollar paid from the public coffers for professional sports stadiums. If the stadium were a good investment, there would be a private investor for it.
Detroit just declared bankruptcy shortly after spending hundreds of millions of dollars on sports stadiums which completely flopped.
The concluding paragraph says it all:
Detroit may no longer provide pensions or adequate municipal services. But it will have state of the art sports venues…for at least a few years…until some other city builds a cooler one.