The world's largest indoor theme park is set to open in Dubai this month to lure back some of the tourists and residents who often flee abroad during the scorching desert summer.

Opening August 31 in a sandy suburb beyond Dubai's concrete jungle and pockets of artificially green spaces, IMG Worlds of Adventure's boxy exterior belies a 140,000-square metre air-conditioned cathedral of entertainment teeming with animatronic dinosaurs, roller coasters, Marvel superheroes and Cartoon Network characters.

Zombies pop out from dark corners of a haunted house and the Velociraptor coaster throttles passengers within a misty simulated rain forest dubbed the Lost Valley.

As it stands now, stir-crazy families in Dubai - a tourism and financial hub which already boasts the world's tallest building - have few places to stretch their legs beyond expensive malls while temperatures outside can approach 50 degrees Celsius (122 Fahrenheit).

Even an indoor ski slope, complete with real-life penguins, has not been enough to stanch the exodus that leaves roads and public spaces eerily quiet through the hot months.

"Dubai still suffers from a certain amount of seasonality during the June, July, August period," Lennard Otto, CEO of the new $1 billion attraction, told Reuters.

"We will hopefully drive tourism in those periods to make Dubai an all-year-round destination," he said, ahead of the theme park's August 31 opening.

"Today there's a gap in this market and in the region. People are actually travelling to the far east and the far west to experience theme parks," Otto said.

Both the UAE, which includes Dubai, and Saudi Arabia have launched initiatives this year to create more fun for their car and smartphone-obsessed people.

As part of a plan to diversify its economy away from oil, Saudi Arabia announced in June that it was in talks with Six Flags Entertainment Corp to build theme parks, and the UAE created a "Happiness Ministry" in February to look at ways of measuring and improving quality of life.

Happiness in Dubai may soon be in no short supply, as a government-backed rival by Dubai Parks and Resorts will open by year's end, while a Fox-branded theme park, with attractions based on TV and film titles such as "Ice Age" and "The Simpsons", is set to open in 2020. - Reuters