When is it safe to walk into a lion enclosure? When a zoo digs a giant tunnel beneath their enclosure and builds a people cage on top.

Welcome to the Predator Experience, a $1.4-million plan by South Australia’s Monarto Zoo based on the success of shark cage diving off Port Lincoln.

In a role reversal of a regular zoo exhibit, it would allow up to 30 visitors into the cage for a close-up experience with the lions while they roam free outside and are fed.

Zoos SA chief executive Elaine Bensted said it was “going to give visitors a chance to quite literally go into the lions’ den” about 45 minutes east of Adelaide.

“Lions are always attracted by food. I think they’re going to be attracted anyway by the fact there are 20 or 30 people in a cage,” he said.

An artist’s impression of the lion cage at Monarto Zoo. Photo: Zoos SA

Ms Bensted said well-known Port Lincoln tour operator Rodney Fox got the idea for shark cage diving when he saw lions being fed at the zoo.

“If you’ve had the opportunity get close to a lion they’re just amazing creatures so to get up close and be able to see a lion or 10 around you, I think, will appeal to people of all ages,” he said.

Ms Bensted believed the lions would be “very” interested in the people inside the cage even when they are not being fed.

The zoo also planned to use the people enclosure for close-up experiences with other animals at the zoo, including hyenas.

SA Regional Development Minister Geoff Brock said the new attraction would boost Monarto Zoo visitor numbers above the current annual level of 130,000 annually and inject about a $1 million a year into the local economy.

The Federal and South Australian governments will contribute half of the funding for the tunnel and people cage, which is expected to be operating by the end of this year.

-ABC