A father from Texas realised there were no theme parks where his disabled daughter could play. So he decided to build one.
Gordon Hartman had just got out of the swimming pool on a family holiday, when his 12-year-old daughter Morgan went up to some children playing in the water. She tried to make friends with them but they quickly left the pool.
Hartman thinks they shied away from her because they didn't know how to react to someone with a disability - Morgan has the cognitive understanding of a five-year-old as well as a form of autism.
The incident played on his mind.
"Morgan is just a wonderful young lady. When you meet her you will always get a smile and she will always want to offer a hug. But there were so many times we couldn't take her places," he says.
Hartman and his wife Maggie asked other parents where they could take their daughter - somewhere she would feel comfortable, and others would feel comfortable interacting with her.
"We realised such an inclusive place didn't exist," says Hartman.
So in 2007 he decided to build it himself. A former property developer, he sold his homebuilding businesses in 2005 to set up The Gordon Hartman Family Foundation, a non-profit organisation that seeks to help people with disabilities. Then he set about creating the "world's first ultra-accessible theme park".
"We wanted a theme park where everyone could do everything, where people with and without special needs could play," Hartman says.
He brought together doctors, therapists, parents and other people with and without disabilities to consult on the facilities. These were built on the 25-acre site of a disused quarry in San Antonio, Texas.
The park, called Morgan's Wonderland, cost $34m (£26m) and opened in 2010. Attractions include a fully-accessible Ferris wheel, adventure playground and miniature train. Visitors regularly tell Hartman it is the first time they've been able to experience such attractions.
There is also a carousel with specially designed chariots for wheelchairs that go up and down alongside the animals. However, Hartman reveals Morgan was at first wary of the ride.
"When we opened she was too scared to go on it. She didn't understand why it was going around and the animals were going up and down," Hartman says.
It was three years before Morgan would go on the carousel.
"First she would stand near it, then she'd get on an animal but we wouldn't start it. It was a slow process but now she loves going on it. Overcoming something she was scared of meant a lot to her. Little things achieved in play can make a big difference."
Since it opened Morgan's Wonderland has received over a million visitors from 67 countries and from all 50 American states. A third of staff have disabilities and entrance is free to any guest with a condition.
"I realised Morgan was one of the lucky ones because she had many of the things she needed. I didn't want cost to be a barrier for others with special needs," Hartman says.
"We open every year knowing we're going to lose over $1m (£750,000) and we need to recover that through fundraising and partners."
This year, the theme park was expanded with the opening of Morgan's Inspiration Island, a fully-accessible water park.
"Fewer people were visiting in July because the wheelchairs got too hot. So we decided to create a water park next door," Hartman says.
Parts of the island use warm water, which helps visitors with muscular problems. Waterproof motorised wheelchairs are provided, which run on compressed air rather than batteries. There is also an accessible river boat ride.
Altogether, the water park cost $17m (£13m).
"Yesterday a man came up to me at Inspiration Island and just held my hand," Hartman says.
"He pointed to his son, who has acute special needs and started crying. He said he hadn't been able to play in water before."
Hartman says three out of four visitors to the park are not disabled, and that the park is having precisely the effect he hoped for.
"It helps people realise that though we are different in some ways, actually we are all the same," he says.
"I saw one girl in a wheelchair go up to another girl without special needs, and they began playing together. That was really cool."
Hartman isn't planning to open any more parks, despite receiving hundreds of letters and emails from people who want one in their own area. Instead he is focusing on providing educational facilities to teenagers with special needs in San Antonio.
"I know there are a lot of different organisations trying to build something like Morgan's Wonderland elsewhere and we'll continue to work with them," he adds.
He continues to take Morgan along to play at the theme park, where she is now something of a celebrity.
"When she comes here she's a rock star! Lots of people want to talk to her and take her picture, she's very good with it," Hartman says.
Now 23, Morgan continues to go from strength to strength.
"She talks more now and most of her physical issues have been taken care of through numerous surgeries. We're so proud of how far she has come."
When Morgan visits she's happiest playing on the swings and in the sand zone, unaware of just how much she has helped others.
"Morgan knows the park is named after her, but I don't think she understands the magnitude of what it represents and how it's changed lives," Hartman says.
"She doesn't realise how she has dealt with things in life has made her a true inspiration."
Pictures were provided by Jerstad Photographics and the Gordon Hartman Family Foundation
Follow Claire Bates on Twitter @batesybates