On the weekend, I watched a documentary called Blackfish. It's about SeaWorld, and how they are cruel to the animals there, specifically the Orcas. Due to the small pools they are put in and the deprivation of freedom, they go mad. It was really sad, yet interesting to hear of all the stories about Seaworld. I would recommend watching this movie. Blackfish, it's on Netflix.
I linked a youtube video below. This video tells the story of one of the orcas that live in Seaworld. This story is lightly touched upon in Blackfish. If you find the following video interesting, I'm sure you'll enjoy Blackfish.