In the river port of Goolwa, there's a little-visited museum called (rather ominously) the 'History Centre'.
It's one of those old regional museums, the sort of place that city visitors skip when they're obsessing about finding a 'good coffee'.
Yet it houses some obscure and significant exhibits that will have you spluttering, "Who knew?!"
"Hello!" says a volunteer in a thick woollen cardigan, "Have you come far?" She gives me a ticket in exchange for $2.50. "Please take your time!"
I discover the wonky old building has served as a blacksmith's workshop and a space where a whole paddle-steamer was assembled in the 1850s. It's now packed to the gunnels with stuff that's been donated and loaned over decades.
A display case houses two wooden scrolls joined by a spool of linen: when you turn one, the other unwinds, steadily revealing a stream of hand-drawn content on 12m of linen.
It's a map of the Murray River, all carefully inked and labeled with bends and landmarks and river ports with their old inns.
It's a recreation of a roll chart, and it's beautiful: 150 years ago, river captains would slowly scroll it as they made their way up or down the South Australian section of the mighty Murray.
The 3750km Murray-Darling system starts as streams in NSW, Victoria and Queensland.
By the time it crosses into South Australia, it's become a magnificent 'old man river'.
In the 19th century, it served as a major trade route, on which paddle-steamers freighted grain and wool to the Murray Mouth, from where ocean-going clippers would load up and take it to the far corners of Empire.
Before I leave the History Centre, I ask the volunteer: "Excuse me, what's the most unusual exhibit you have?"
The volunteer thinks for a while. "Well in the room behind here you'll see Australia's first motorhome."
I regard this with some disbelief, but sure enough, within a dark space is a little house with a roof and eaves and gutters – and it's built onto the back of a 1929 Dodge Tourer.
When a Mr Kaesler took his family on holiday he found the local seaside cabins were booked out; he was so miffed that he decided to modify his jalopy.
Amazing what you find when you take the time to look.
Why are we here? We've crossed the border from Victoria to begin following the Murray's final 350km before it reaches the sea.
Renmark is a substantial centre in the Riverland, with wide generous streets, serving the huge fruit and wine growing district.
Many civic parts of the town were effectively 'crowd-funded' at the turn of the 19th century. The Renmark Hotel has been owned by the community since 1897, the first of its kind in the British Empire.
There's possum magic on the lawns of the Renmark Riverfront (opposite the Hotel) when the local critters come down from the trees.
River notes: Renmark, along with the nearby towns like Paringa and Murtho sit in a section of convoluted meanders surrounded by substantial nature-filled creeks and backwaters.
One of the best ways to explore is by kayak. Canoe the Riverland hires craft and leads tours, including a tour under the full moon.
In the Riverland, the Ngarrindjeri people lived on and along the lands around the Murray; look out for 'canoe trees' – old river gums showing scars where bark has been taken to make canoes. Today, the Ngarrindjeri remain South Australia's largest Aboriginal community. Acclaimed Aboriginal artist Ian Abdulla was from the Murray River region.
Other highlights: Ruston's Rose Garden and Visitor Centre is the largest rose garden in Australia, with some 50,000 roses. The Wilkadene Microbrewery in Paringa is a riverside beer and cider maker in a 100-year-old shearing shed.
Who knew? Soldier Harry 'Breaker' Morant worked locally, at J.F. Cudmore's Paringa Station in the 1890s, before going off to the Boer War. The station is beside the lovely Paringa Bridge – right next door to South Australia's newest luxury retreat, The Frames. Stories exist of Breaker Morant riding his horse up to the bar in the Renmark Hotel.
Why are we here? We've done 110km heading west-ish from Renmark, a journey that entails stops along the river at several significant historic and natural attractions.
Morgan was once home to hundreds of paddle-steamers, as evidenced by the remains of wrecks up and down the river (many of them favoured by fisherman as 'honey holes').
The former glory days of riverboat captains and valuable river trade don't seem so far away in the restored Wharf Precinct and the Landseer Building, a shipping agent's storehouse now housing a collection of old engines and wagons.
Houseboat hire is available in Morgan.
River notes: The Murray is still complex and convoluted, with the main water body describing rich meanders and carving through red sandstone to leave stretches of spectacular river cliffs.
Clifftop lookouts can be reached on driving loops.
Creeks, oxbow lakes and freshwater lakes sustaining the rich food basket landscape as well as the Murray River National Park, is a substantial conservation area.
The Park is some 13,000ha of significant floodplain environments – think sunken forests of massive gum trees – and comprises three sites, Katarapko, Lyrup Flats, and Bulyong Island.
It's popular for fishing, kayaking, and for the watching of prolific birdlife, including pelicans, kingfishers and parrots.
There are two riverside heroes en route to Morgan.
The Overland Corner Hotel is a stellar little pub established in 1859, filled with stories of highwaymen, pastoralists and at least one ghost.
Banrock Station is a successful international wine brand that still returns profits to its wetland operation: walk the extensive boardwalks then repair to the elevated restaurant deck for a glass or three.
Other highlights: Loxton is home to The Village, a recreation of mid-1800s riverbank life using (mostly original) buildings.
At Cobdogla, the Irrigation and Steam Museum sees the world's only surviving Humphrey.
The towns of Berri and Barmera are important fruit and wine growing towns with plenty of both on sale at farm gates and cellar doors. Both offers cruises and canoe trails.
Waikerie is home to art galleries, cliff-top walks, a well-regarded golf course and a purveyor of fine breads/pies/cakes, satisfyingly called the Waikerie Bakery.
Who knew? Donald Campbell attempted the world water speed record on Lake Bonney near Barmera.
Weather wasn't ideal and his speed of 216mph fell short. The Bluebird Café on the lake shore outside Barmera is a strange-looking thing but it's where the Bluebird K7 was housed for the event in 1964. The fish and chips are reportedly very good!
Why are we here? We've done a 130km drive south from Morgan and enjoyed at least one signature river-crossing by car ferry at Swan Reach and/or Mannum.
We've weighed anchor at Mannum for houseboats, paddle-steamers and history. Built into the side of steep river cliffs, much of the town enjoys views over the river and has a distinct holiday flavor.
It's the headquarters of several houseboat rental companies (including a few that offer well-appointed luxury craft with top-deck spas); it's also the departure point for the Murray River Princess paddle-wheeler offering week-long river cruises; and the fine Pretoria Hotel has a garden that goes right to the water's edge.
River notes: The Murray is on the home straight to the sea, cutting a deep path south. The river is wide and lush, with frequent braiding around wetlands that are rich with birdlife.
Some of the most widely photographed river cliffs are here courtesy of an operation that's being going for over a decade – the Big Bend at Night Tour. Based on a farm not far from the charming town of Swan Reach, it's all about nocturnal wildlife and the Big Bend cliffs lighting up at sunset.
Houseboat rentals are popular around Mannum owing to the long stretches of beautiful scenery and the open cruising waters (which means you won't meet a lock!). Depending on the level of luxury you require, count on paying from around $400-$600 a night for a boat that sleeps eight.
This includes just about everything except food (and there's usually a fishing rod to help with that) and fuel. Houseboats are easy to sail; a driver's license and some common sense is all that's required.
Other highlights: The Mannum Dock Museum and PS Marion tell the story of how Captain William Randell launched the first paddle steamer here in 1853, winning a purse for himself and ushering in Australia's glorious river history.
Mannum Waterfalls are surprisingly lovely and great for a swim in summer. Swan Reach is definitely worth a visit – an unusual town with an equally unusual hotel built around a homestead building.
Who knew? The first Australian-made motor car was produced in Mannum. The Shearer Steam Carriage first chugged through Main Street in 1899, 14 years after local implement manufacturer David Shearer set himself to making a 'horseless carriage'. The vehicle is in the National Motor Museum in Birdwood, in the Adelaide Hills. Shearer's house (and the remains of his observatory) can be seen on the hilltop behind the Main Street.
Why are we here? Because, like the river, we've done our final 100km and reached the sea.
Goolwa is a remarkable little town on so many levels.
Firstly, it was a river port, or more exactly the terminus where the paddle-steamers unloaded their cargo. But! Cargo couldn't actually get through the river mouth (which was treacherous with sandbars) so it had to be transferred to jetties on Encounter Bay where ocean-going ketches lay in wait. Cue a horse-drawn railway – and indeed, the nation's first passenger rail operation.
From Goolwa you're perfectly positioned for some unusual perspectives: you can see the Murray Mouth, via Hindmarsh Island. You can cruise out to see the famous Coorong.
And you can explore the dramatic south coast, home to dolphins, seals and (from June to October), visiting humpbacks and Southern Right whales.
If this isn't enough, Goolwa also has an awesome beach on the Southern Ocean, loved for its sun, sand and surf.
River notes: En-route from Mannum we've passed through Murray Bridge and Tailem Bend with Australia's biggest river continuing to look like a sedate old madam. But at Wellington, she loses the plot, turning into an incredibly complex piece of estuarine geography. Behold lakes that look like small seas, incredible sand islands, fearsome tides meeting powerful ocean currents and a river mouth that looks nothing at all like a river mouth.
Just to confuse things even more, the coast has thrown up a 100km-long narrow barricade of sand dunes across the lot.
This is part of the extraordinary Coorong, comprising 100km of ocean-facing dunes that protect one of the most significant freshwater ecosystems in Australia. It's also the country made famous by the novel and movie Storm Boy.
Other highlights: Murray Bridge has canoe and ski boat hire – as well as a terrific canoe trail in and around the prominent railway bridge. Nearby Monarto Zoo is the largest open range zoo in Australia and home to whopper Southern White rhinos.
The lakes are home to rather nice wine estates and cellar doors like gorgeous Bremerton Wines. Canoe the Coorong and Spirit of the Coorong can help you make sense of the singular local ecosystems with guided tours. Goolwa's Steamranger and the Cockle Train offers a scenic rail ride sur mer.
Who knew? Goolwa was the first Australian town to become a 'Cittaslow town'. This is bestowed by the Italian Cittaslow movement, which believes life is best lived slowly and food is best sourced locally. Try The Whistle Stop Restaurant, or the set menu dining at The Australasian Circa 1858.
This article brought to you by the South Australia Tourism Commission.