A MAN who died after plunging 20 metres down a ravine was taking part in the treasure-hunting activity of geocaching, police say.

Police, MFS and SES crews were called to Waterfall Creek, off Drugal Ct, about 1.20pm on Monday in response to reports a man had fallen down a steep ravine.

media_camera Police and emergency services at the bottom of a ravine in Hallett Cove, where a man fell to his death on Monday. Picture: Roger Wyman

media_camera The ravine down which the man fell. Picture: Roger Wyman

Police say the Enfield man, 66, was geocaching with his wife when it appeared he slipped and fell at least 20 metres into water below.

The man’s wife was supported by her sister as emergency services waited for the coroner to arrive.

A stretch of Drugal Crt was closed off as emergency services massed to recover the fallen man.

Local resident Richard Snell said he had first-hand knowledge of how dangerous the steep cliff could be, having slipped down it himself.

“About two years ago I was showing my mate Derek a beehive down the slope and slipped on the dry grass,” Mr Snell said.

“I ended up on my back on a flat rock ... one wrong footing and you’re gone. Maybe they need to fence it off.”

Another neighbour said they knew something was seriously wrong when they saw the man’s wife in distress.

“I only saw his wife when I came out. She was extremely traumatised, she was shaking,” they said.

media_camera The man died after he fell while geocaching. Picture Roger Wyman

“You could tell he was gone by the speed which they recovered the body, there was no urgency.

The neighbour said they were not aware of similar incidents in the area.

“No one has fallen down there to my knowledge. A mate of mine slipped down part of the way but not to the bottom,” they said.

Geocaching involves the use of GPS to find hidden containers, called caches, at set locations all over the world marked by co-ordinates that are shared online by the sport’s participants.

Caches are left by other enthusiasts and usually hold a log book for people to sign to prove they’ve found it.

Police will prepare a report for the Coroner, however the man’s death is believed to be accidental.

The tragedy comes as another man fights for life after the car he was in rolled up to 20 times along a ravine before plunging 25m down a steep embankment south of Adelaide on Monday.

And an elderly woman fell three metres while at Morialta Falls about 5pm on Monday afternoon.

The woman was retrieved by helicopter after emergency crews became reluctant to carry her out because night was close.

Crews first on the scene hiked up to the woman, about 45 minutes walk from the closest car access point.

Her injuries are unknown at this time but they say she’s in good spririts and chatty. She was taken to the RAH.

How does geocaching work?

Is classed as an outdoor recreational activity similar to a treasure hunt or orienteering with specialist clubs across the world.

Participants use mobile phones, GPS devices and other navigational tools to find any of the millions of “geocaches” dotted throughout the globe.

A typical geocache is a waterproof container such as a Thermos, ammunition box or lunch box. It contains a log book which participants sign and date then return to the exact location it was recovered from.

According to an official Geocaching app, there are almost 4000 geocaches in the Adelaide area.