But something revolutionary is happening in the flatlands of Tennessee. Deep roars can be heard through trees that shield neighbors from an unlikely sight, one that is hidden from the main roads. A kind of asylum exists for previously dangerous or deprived elephants in captivity, now living the rest of their lives here in the semi-wild. Driving past the perimeter fences, an awareness that huge animals are nearby and unseen evokes comparisons to Jurassic Park, but with a therapeutic mission. The Elephant Sanctuary, a private nonprofit organization in Hohenwald, Tenn., spans 2,700 acres of forests and spring-fed ponds.
This is a last refuge for elephants broken by humans, and they are here to heal. But doing so requires the elephants' ultimate act of trust in humans.
On a recent visit, ABC News correspondent Elizabeth Vargas was chaperoned inside the gates to discover an intimate world.
"She has her ears out so she's checking it out. And since she's the matriarch it's her job to make sure that everything is safe. It's a sign of trust and intimacy," said Carol Buckley as she approached an elephant named Shirley.
Buckley and Scott Blais, co-founders of The Elephant Sanctuary, establish trust with the animals, guided in part by the new theory that if humans and elephants can both suffer from Post-Traumatic Stress Disorder, maybe we can also share the hope for recovery.
"What we have learned, and what we have seen, without a doubt, they are experiencing some level of Post-Traumatic Stress Disorder," said Blais.
Creating a safe environment is vital to the progress made at the sanctuary, where 17 former circus and zoo elephants walk without chains or threat of abuse.
Applying techniques used to treat humans suffering from PTSD, Buckley and Blais research how these elephants have been stressed in the past, their responses, and tailor the sanctuary's programs to help each one.
Elephants once dangerous and isolated in captivity discover how to play again with new friends.
"They operate on a much deeper plane than we do, and you can't help but be fascinated with that," said Blais.
It's a sentiment Buckley shares.
"I think that's what happens with people who are around elephants. There's some profound connection that is made that is deeper than we have ever experienced before," she said.