The importance of the 19th century travelling circus on culture and entertainment can not be overstated. It brought animals that were biblical, peoples that were culturally fascinating and entertainment to communities on such a grand scale that they would desperately travel 75 miles by cart to see it. Many circuses failed within the first two years. I would like to see a circus purchased by faith that could add +5-25% culture and 1 amenity to a city for 10 turns. Sometimes the Amenity issue can take many turns to permanently resolve, so at a cost (with an exceptionally realistic historical narrative), you could expend faith by buying a unit to stabilise a city and increase cultural output with a successful performance. It would only perform on a city without the buff in place but once it drops they can return.