Churchill, Canada

In the very northern reaches of the Manitoba Province in Canada is a small city that goes by the name of Churchill. In 2016 the population was roughly 900 people. It's a relatively normal, small town (although the local average temperature probably does not seem normal). However, there is one thing that makes this small town so different. It is built smack dab in the middle of a polar bear migration path. In fact, during certain times of the year, polar bears are almost equal to the human population, coming in at about 800. While it is now clear that this location was a poor decision the founders were either unaware or, the town being as small as it was, it caused no problem at the time, it only provided a food source. After years of dealing with polar bears entering the city and causing problems (attacking cars, attacking people, and the eventual death of a child) the city decided to use an old airplane hanger as a jail for the bears. There is a hotline anybody can call and report a sighting. The bears go to the jail only if they are too close to the center of the city, the place where the residence of the city live. If the bears are in the outer rims of the city an attempt is made to scare them away. If they get closer they are shot at with rubber bullets (so as not to permanently damage them). This system has worked wonders for the city. 

This is only a brief summary of the real life bear jail. Many reliable newspapers, magazines, and news shows have made much more in-depth, well-written, whole picture articles and videos about the subject. These including The Atlantic, ABC News, and VICE News. Please check them out to learn more about the specifics:
The Atlantic: Bust Times at the World's Largest Polar Bear Prison 
ABC News: The World's Only Polar Bear Jail
VICE News: Polar Bear Prison