Until 2002, the Southern Ocean didn’t actually exist – at least on maps.

Hydrographers argued that it was merely the southernmost bits of the Pacific, Indian and Atlantic Oceans reaching down to the Antarctic landmass, where the waters simply got cleaner and colder.

But the Ocean, now duly classified and considered the fourth-largest of the world’s five great oceans, is perfectly distinct.

The Southern Ocean Drive, extending some 450km from Adelaide to Mt Gambier, is similarly distinct.

If you’re crossing the border into Mount Gambier, then you’ve probably come off Victoria’s Great Ocean Road, with its picturesque ribbons of surfside bitumen winding through forest groves and pretty beach towns.

The Southern Ocean Drive takes broader strides into wider horizons, including the Coonawarra wine region, the remarkable wetland phenomenon of Coorong, and the famous wildlife haven that is Kangaroo Island.

The following is a series of sequential stops on the Southern Ocean Drive. You can string them together depending on the time you have for the journey. Or of course you can make like the Southern Ocean – and just go with the flow.

Mount Gambier

Why: The sleepy town of 27,000 was once a hotbed of cataclysmic volcanics, and you don’t have to look far to find a relic of its fiery past. The town sits alongside a crater filled with the famous Blue Lake: visit before early November and the lake looks grey; then, almost overnight, it changes to a radiant blue affecting to a deep turquoise, a colour that stays until February. The town also has a number of sinkholes (limestone caves), including one converted to a stunning sunken garden by James Umpherston in 1886. His eponymous garden is especially charming at sunset when the possums come out to play.

Penola 

Why: The rest of the world found it miraculous that Australia could produce a saint, but so it was, thanks to Mary MacKillop (1842-1909) who was canonised in 2010. At the Mary MacKillop Interpretive Centre  you can visit the schoolhouse where she taught poor children from the bush; her story is told by volunteers in lovely surrounds. The small town has plenty of charm, lots of heritage and some decent vintage shopping.

Hallowed names can also be found just outside Penola, which is the gateway to the Coonawarra, the part of the Limestone Coast wine region that’s famous for its red soils and red wines. The Riddoch Highway is a veritable gauntlet of good stuff, including cellar doors belonging to Wynns Coonawarra Estate, Hollick Wines, Zema Estate, Balnaves of Coonawarra and Rymill Coonawarra.

Naracoorte Caves National Park

Why: In 1969, explorers entered Victoria Fossil Cave and discovered huge quantities of fossilized remains. They’d discovered what was once a trap: animals that lumbered around 200,000 years ago fell through a hole and into the cave where they perished. Today this is one of 28 known caves within the World Heritage Listed Naracoorte Cave system, offering evidence of life from several ice ages including the marsupial lion, thylacine and a giant kangaroo which scientists believe walked rather than hopped. Today, visitors can go underground to encounter bones, rare bent-wing bats and dramatic rock formations: you can do it in a nice-n-dry fashion; or suit up with overalls, kneepads and helmet to get down-n-dirty.

Robe

Why: The pretty fishing town of Robe is loved for the family-friendly Long Beach, 80-odd heritage buildings, the Third Ramp surf break, year-round fishing and locally caught rock lobsters. A holiday seaside town if ever there was one.

Goolwa

Why: Goolwa is your best place to properly see (and for that matter understand) the complex wetland system that is the Coorong. Spirit of The Coorong  offers two-hour and up to six-hour cruises into the 140km long lagoon of fresh and salt water, fringed by huge and ancient dunes on the Southern Ocean. Expect to encounter Aboriginal heritage, birdlife, Colin Thiele’s Storm Boy and wild, wild seascapes.

If you’ve got time: Explore Goolwa. This rather cute and historic port is located where the Murray River ends its journey across the nation to arrive at the sea. It’s also where paddle-steamers used to unload their cargoes onto horse-drawn rolling stock for overland shipment to sea ports in Port Elliott and later Victor Harbor.

Victor Harbor

Why: Victor is an impressive-looking town, backed by hills and fronted by a famously misspelled harbour complete with an unusual island at the end of a long pier with rails. This is The Causeway: start here to get your bearings, as well as to meet the Clydesdales that pull the last of only two horse-drawn tram operations in the world (the other is on the Isle of Man). It’s been in operation since 1894. Let them take you out to Granite Island, and be sure to do the circular Kaiki Walk to enjoy views up and down the dramatic coast.

For a closer look at the marine action, join a Big Duck Boat Tour. You’ll travel in a powerful rigid inflatable boat to see dolphins and seals; if you’re visiting between May and October, you’ve got a good chance of seeing visiting humpbacks and Southern Right whales which come here to breed.