Lake Burrinjuck: Everything you need to know about this watery wonderland

However, just over the hills to our west is a lesser-known watery wonderland. Sure, it's man-made, but with a capacity more than 30 times that of Lake Burley Griffin (or almost half a million Olympic-sized swimming pools or two Sydney Harbours), Lake Burrinjuck is a magnet for adventurous weekend warriors.

One Canberran who regularly beats a path to Lake Burrinjuck come Friday knock-off time is Bruce Ronning of Conder.

For several years in the mid-1970s, Ronning's family ran the small tourist park at Woolgarlo, on the Yass River arm of the lake.

"As a child, living there was really quite special. I have fond memories of not only a rural lifestyle but also learning about the lake itself – it was my backyard," Ronning recalls.

Unlike most of today's visitors who flock to the lake's glistening waters for water skiing or fishing, Ronning especially liked "to just explore".

"I loved discovering out-of-the-way places like secret caves, hidden mines and wondrous waterfalls," says Ronning, who still returns several times a year to take his own kids there.

"It's great to see they've developed their own affinity for the place - camping, fishing, exploring, all those things I did as a kid."

Lured by the prospect of discovering some of Ronning's childhood haunts (oh, and a swim), your akubra-clad columnist recently joined Ronning for a day exploring the lake on "Goodoo''', his 5.25-metre Stacey Bowrider motorboat.

One of the most accessible places to launch is from Good Hope boat ramp, about 20 kilometres from Yass. On the day of our visit, the lake is less than two-thirds full, which means there's a long stretch of desolate shoreline to negotiate before reaching the water.

It's mid-morning and to compensate for a lack of natural shade, the foreshore is already dotted with dozens of picnic gazebos erected by adrenalin junkies for their friends to sit in, while they whizz past on tubes and water skis.

As we launch, a flock of pelicans gaze quizzically at us, seemingly perplexed as to why we don't have a tow rope or fishing lines trailing in our wake. People only come to Burrinjuck to ski or fish, don't they?

Once on the water, the first thing you notice is the lake's size, with a water surface area of 5500 hectares (about 8000 football fields) it really is vast. Also noticeable is the plethora of geological formations both above and below the high water mark.

"The whole Burrinjuck area is fascinating geologically and as a 10-year-old with an interest in rocks and fossils I was in paradise," Ronning says as we approach a conical-shaped hill rising out of the water with a pattern of rocks running through it almost too symmetrical to be natural.

Concealed beneath one of these gravity-defying geological formations is the entrance to Ronning's most cherished childhood hideaways.

"If I heard that someone was coming here, I'd always want to tag along," says Ronning as we tie the boat to a rock on the shoreline and proceed to crawl up a creekline into a gaping chasm in the side of a hill.

Expecting a small cave or rock overhang, I'm astounded as Ronning leads me by torchlight further and further into the abyss, which is clearly not a secret to everyone for many of its cave decorations have been obviously exploited by selfish visitors in years gone by.

"Sometimes there is a fair bit of water and you have to wade through here," Ronning says, crouching as we stop near a muddy part of the underground creek to inspect a pile of what appears to be wombat droppings.

"As a kid, there was a local legend that a wild dog of some sort lived in the cave," Ronning says. , While he never saw the sharp-fanged denizen, he does recall "writing a story for the school newspaper about finding a half-eaten kangaroo carcass at this exact spot".

With its curious chambers and crawl-throughs we could explore the cave for hours, but Ronning has other ideas.

"This is just one of many special spots on the lake," he says as we head back into the light.

From here, it's like a Choose Your Own Adventure book.

"One arm of the lake leads to Maceys Bay and a waterfall which flows after good rains, another to Cave Rock – a flooded cave popular in the past with divers, and yet another to the old mines," he says.

Given we're in the middle of a dry spell and we have no compression chamber (nor scuba gear for that matter!) on board, I opt for the latter.

"As a kid, when I looked across from Woolgarlo I could see these old mines … they were irresistible for a 10-year-old boy," Ronning says. He ventured over a few times and sifted through the pits for chunks of quartz laden with lead and copper.

But it's not a few pieces of scrap metal that Ronning best remembers this far flung part of the lake for. This is where, in 1976, aged just 10, Ronning caught his first Murray Cod, weighing in at 6.5 pounds, while trolling a "green flatfish" lure.

"An old fellow known only as 'The Dutchman' took me out on his regular afternoon run," Ronning says. He still has a photo of the prized catch.

"Cod are a very special fish," he says. He remembers "the precise location of every single one" he caught. Little wonder his boat, Goodoo, is named after an indigenous word for Murray Cod.

Today it appears as if a road has been graded over most of the site but near the high water mark we do see an entrance to one old shaft, or is it a giant wombat hollow? We don't uncover any treasure, just the bones of a kangaroo or two guarding the entrance.

For many Australians, summer childhood memories involve the coast, but for Bruce Ronning it's all about Lake Burrinjuck, one of our region's biggest and most surprising inland waterways.

Lake Burrinjuck: Wedged between Wee Jasper and Yass, the lake is accessible at several locations including Good Hope Resort which is 20 kilometres south-west of Yass. More: www.goodhoperesort.com.au. For general information on access to the lake and its foreshore, see www.stateparks.nsw.gov.au. As with any inland waterway, adhere to local regulations, seek permissions if venturing onto private land and most importantly, take care.

Did You Know? Construction of Burrinjuck Dam, the first major dam built for irrigation in NSW, began in 1909, but due to delays caused by the labour and material shortage during World War I, the original design was not completed until 20 years later. At the time of construction, it was the fourth largest dam in the world.

Ancient graveyard: The limestone under and around Lake Burrinjuck has produced the most diverse Devonian fish fossils (around 400 million years old) anywhere in the world – so far more than 70 species have been found, including many undescribed forms.

Don't miss: The giant 52kg Murray Cod mounted on the wall at the Yass & District Museum (247A Comur St, open 10am-4pm weekends, adults $5) that was caught in the Murrumbidgee River arm of Lake Burrinjuck in 1977.

At least it's not quite as gory as the mounted head of another cod (pictured below) that greeted patrons for many years at the (now closed) Wee Jasper pub.

Tim's Tip: If you don't have your own vessel and can't twist the arm of a friend who does, the NV Getaway which operates from Reflections Holiday Parks Burrinjuck Waters, offers a number of scenic tours of the lake. From $30 per person, bookings essential. Ph. (02) 62278114.

Cryptic Clue: I doubt Ben Chifley played totem tennis here.

Degree of difficulty: Medium

Congratulations to Belinda Barnard of Watson who was the first reader to correctly identify last week's photo, sent in by David Osmond of Dickson, as the old bubblers located between Dickson College and Antill Street. With the proliferation of designer water bottles these days, bubblers of such antiquity are fast becoming a dying breed.

How to enter: Email your guess along with your name and address to timtheyowieman@bigpond.com. The first email sent after 10am, Saturday February 10 will win a double pass to Dendy.