Swimming face-to-face with a massive saltwater crocodile might not be everyone's idea of fun but thrill-seekers are snapping up northern Australia's new tourist attraction.

Tourists who want to get cozy with a crocodile climb into a clear acrylic cage, dubbed "the cage of death," which is about 145 mm thick and 2.8 metres high, wearing just a pair of swimming goggles and a swimsuit.

The cage has no bars, unlike cages used in shark dives, which prevents the reptiles from gripping on but deep teeth scratches are visible on the sides, deterring some hesitant participants.

The cage is then slid along runners over four crocodile pens, carrying a maximum of two divers at a time, and partly immersed in the water so swimmers can see the crocodiles under the water but also come up to the surface for air.

The attraction, located at Crocosaurus Cove in the heart of the northern city of Darwin in the Northern Territory, was given high marks by adrenaline-junkies.

"This is it!" said self-confessed thrill-seeker Mark Clayton from Darwin after spending 20 minutes in with the crocodiles.

"I dive with sharks, large rays, moray eels ... but it's not this close. It's exhilarating to get that close to a crocodile of that size."

Saltwater crocodiles, known locally as "salties," are the largest crocodile species, with the males growing up to 6 metres long and weighing up to 1000 kgs.

They are found in across Southeast Asia but the highest numbers are found in northern Australia.

Michael Scott, who opened the attraction in July this year, said there is plenty of demand for the A$83 thrill with the venue even boasting one celebrity croc, the 5.1 metre long Burt who starred in the Australian movie Crocodile Dundee and nearly ate actress Linda Koslowski's character.

"In the Northern Territory, the saltwater crocodile is an icon and is part of our life. They are always in the news, either in someone's swimming pool or killing someone's favorite horse," Scott told Reuters.

However he said "the cage of death" was not for the weak hearted but for those who like to dice with danger and enjoy activities like bungee jumping or swimming with sharks.

"It's for the adrenaline junkies," he said.

Although saltwater crocodiles are dangerous, fatal attacks on humans are rare in Australia with only one or two reported a year and warning signs displayed at rivers, lake and beaches in areas inhabited by crocodiles.

The most recent fatality was reported last month in Queensland when the suspected remains of a British man were found inside a crocodile. Arthur Booker, 62, was last seen checking crab pots on a crocodile-infested river in the state's north.