Gathering steam at the Waipuna Junction railway

The cleverly designed track gives the illusion of going on a long journey.

Waipuna Junction railway station is sure to appeal to both young and old. Stephanie Chamberlain hops on for a ride.

It's been a long while since we took the Peterson Rd turnoff from Waipuna Rd to the model railway beside the Waipuna Conference Centre. My last visit can be measured in decades - three, if you must - but I clearly remember the rush of cold air and fascination of watching a driver stoke a tiny coal engine. It's a pleasant surprise to find that the volunteers at the Auckland Society of Model Engineers are still going strong and offering affordable train rides every Sunday afternoon.

From the carpark it's a short walk past an icecream truck and a playground (yes, we're weak and there are promises to visit both later) to the Waipuna Junction railway station. A friendly conductor issues us tickets; bless him, he understands the importance of this moment to the children and adds a flourish of solemnity.

Soon the train chugs in. It's an electric locomotive, although a steam engine is not far behind. The passengers disembark and we're ushered on board.

Tickets are clipped, a whistle blows and we're off. The children sit in front of me, alert with excitement.

The railway is a sophisticated rig - "the cleverly designed track gives the illusion of going on a long journey", the website says- and indeed we seem to leave Waipuna Junction far behind as we chug along a track that twists and turns to take in tunnels, bridges, an elevated trestle, views of the lagoon and arching trees. We get up to a killer 8km/h so the 860m track takes a mere four minutes to complete.

When we pull into the station the girls are keen for another ride but my boat-mad nephew is desperate to head to the adjacent boat pond, where another group of kindly volunteers operate a fleet of remote-controlled launches.

Here, $2 buys five minutes as the pond-side captain of a sleek retro vessel. It's long enough for our kids to have a good bash (literally - apologies to the Scale Marine Modellers Club - I take responsibility for our kids' spatial awareness genes, or lack of them.) Then it's back for another go on the train, followed by icecreams and a swing at the playground that sits under the enormous trees at the lagoon edge.

We notice the steady flow of dog-walkers and joggers so we decide to see how far we can get around the lagoon. A minor protest from the short-legged ones ensues but they're soon won over by the winding pat.

A 15-minute stroll past mangroves and clear stream takes us as far as the Panmure Lagoon Sailing Club clubrooms.

Here there's another delightful wooden playground, this one with tandem slides. Built in the style of a fishing boat and set on sand, it appeals to the kids and they strike up a game of hide and seek.

When we start to wander back we spot a grey heron fishing in the half-tide, a rather fabulous resident for an environment pressed so closely by motorways and industry. Nearby Mt Wellington shines green above us and inspires a teaching moment about how the crater-shaped lagoon would have been caused by a volcanic explosion.

Later we learn that this is a place of more unusual history than we'd supposed. A second, younger volcano lies buried beneath the basin. It was discovered in 2008 when scientists drilled below the basin, hitting scoria at 16m and from it identifying the presence of a 10,000-year-old volcanic cone.

Need to know:

* The Auckland Society of Model Engineers' railway, Peterson Reserve, Peterson Rd, Panmure.

Open every Sunday afternoon 1 to 4pm, weather permitting, except long weekends over Christmas and New Year. Open days are held regularly and advertised. The club meets monthly. Excitingly, members get train-driving lessons, free rides for families and can use the track for their own projects.

Tickets $2 a ride or six rides for concession $10.

* Scale Marine Modellers (Auckland)

* Panmure Lagoon Sailing Club