The underworld right beneath your feet you didn't know about

The underworld right beneath your feet you didn't know about

Our biggest city has a dark underworld many of you won't know exists.

Don’t worry, it's not as seedy as it sounds and in fact, its main visitor is a perfect English gentleman.

In an unassuming suburban garage, you'll find a secret portal to a whole new world and it's where the man dubbed the Attenborough of Auckland's underworld is most at home.

73-year-old cave fanatic Peter Crossley has spent his career charting 250 lava caves and he could be scurrying under your street and you wouldn't even know it.

The tunnels are formed from fiery lava when the surface solidifies and the liquid core drains away.

In half-a-century he's made some fascinating finds including sacred Maori burial sites, a moa bone and mysteriously, a dozen abandoned walking sticks.

It was his ability to bring a hole in the ground to life that attracted young director Gemma Duncan who has now talked him into a film called "Meet Peter".

Watch the video for the full Story report.