From the outside places like zoos and aquariums seem very educational and beneficial to the animals.. but that isn't always the case. More times than not animals are forcefully taken from their native land or born into captivity, living their whole life behind bars as entertainment.
Taking these wild creatures from their homes puts a tremendous amount of stress on the animals, and more animals living in captivity are showing signs of Zoochosis. Zoochosis is abnormal repeated behavior such as pacing or circling back and forth, bar biting, and over grooming/ self-mutilation of zoo animals due to human-induced stress.
Animals living in captivity live significantly shorter lives, not being able to live up to their full potential because they live an artificial life and are often times taken from their families which puts more stress on the animal. Zookeepers don't always take the best care of these creatures either. Some zoos have been temporally and even permanently shut down due to the maltreatment of their animals, such as lack of medical attention, poor sanitary living, and neglecting basic needs.
Taking an animal from their homes and families, to put them in a small artificial replica of their habitat for our entertainment is inhumane and by visiting zoos and aquariums giving to the poor treatment and care of species that were roaming the earth long before humans. Don't get wrong there are great programs that rehabilitate and release animals back to the wild.