Sydney: Action packed

The imposing Opera House dominates Sydney's well patronised waterfront. Photo / Tourism NSW

"They're having a divorce." At Sydney Wildlife World, an icecream-smudged boy of about four points at a wombat and wallaby, who look distinctly unimpressed with each other.

Spotting my suppressed smile, his harried mum hurries her charge along. And I remind myself why I'm spending precious hours here on a short Sydney trip: to see a koala for the first time.

Rounding a corner, I spy what looks like chunks of carpet stuck to a gum tree. Contrary to the myth, koalas aren't drunk on eucalyptus oils, says a keeper, just perpetually "sleepy and cranky".

You can't help feeling they've got a raw deal. Clutching at a tree, the koala sleeps about 20 hours a day. But I've arrived just as their keepers carefully disengage them to have photos taken with tourists.

Ten minutes later I step back into the ubiquitous sunshine at waterfront hub Darling Harbour, and try to decide where to go next. The menu is overwhelming.

Flash your See Sydney & Beyond Smartvisit Card and you get free entry at 40-plus attractions in the city and environs: everything from bus to walking tours, historic houses to harbour cruises; museums to Manly. I'm doing the A$165 ($200) three-dayer, but the week-long pass costs just A$225, and the one-dayer's worth A$75 even if you just make a few stops.

Next door to Wildlife World, the Sydney Aquarium also lays claim to the title of Australia's number-one attraction. Its underwater oceanariums are a must-see, if just for Mermaid Lagoon.

A wall-painting of the ocean is peopled by pirates lured to the depths by "mermaids" who, as legend has it, turned out - disappointingly - to be dugongs. Of just five in captivity anywhere in the world, two are here.

As we're underwater, traipsing through tunnels, I walk looking up, my neck craned at an awkward angle. Those sailors must have drunk a fair few tots of rum to mistake a dugong for a siren of the sea. A distant cousin of the elephant, it looks more like a cross between a hippo, seal and whiskered old man. Alongside it, a shark zigzags past and schools of rabbitfish practise synchronised swimming.

Past a potbellied seahorse, turtles sleeping with their heads in the ground and legs in the air, and sea dragons without discernible faces, I hear an Aussie tell his mate the fish are making him hungry. I couldn't eat one after looking them in the eye, but I'm due for a kebab, and decamp outside.

Although Darling Harbour's a one-stop tourist shop - cafes, a mall, big-ticket attractions - I'm not drawn to its in-one-end, out-the-other commercial core. Too shiny and prettily packaged.

I prefer Circular Quay, the waterfront at the other end of the CBD. Less circular now because of reclamation, it pulses with people: some taking their time, some scurrying for ferries.

Buskers, musicians, statues and sculptures are reasons to stop. Here people really use the waterfront and public spaces, putting Auckland's concrete-stretch Viaduct to shame.

One way to get your bearings in Sydney is to take a lift (or 1504 steps) up the 305m Sydney Tower. Who knew Sydney had so many tiny islands, and fingers of land grasping at the harbour? The 'burbs extend endlessly in each direction. One of the world's largest cities by area, Sydney, at 1580sq km, is twice the size of New York, and 15 times the size of Paris.

I peer through a telescope. From one angle, shiny high-rises sandwich the Opera House; from another they dwarf colossal churches. Out another window I spy The Rocks, the historic precinct so named because all the first sailors could see was a wall of sandstone along the shore. Literally carved out of the rocks, the area is now a painstakingly preserved shanty town. With its cobblestoned streets, narrow lanes and old apartments with potplants spilling over the balconies, it feels more like the backstreet lanes of Spain than Australia.

It wasn't always so charming. By 1860, as I discover on The Rocks Walking Tour, this was a slum full of drunkards, criminals and "fallen women". At an old sailors' house set up to rehabilitate vice-worn seamen, you can almost smell the sweat, see the rats and sniff the tipple of choice: Blast Your Skull Off, a blend of wine, rum and opium with a dash of cayenne pepper.

When the bubonic plague struck in 1900, the authorities bowled a third of the area. In the 1960s and 70s, residents who refused to be forced out saved it from demolition.

Tired from my trekking, I stop at a waterfront cafe, where I hear much squalling and shrieking. It's not the seagulls, but sopping-wet punters returning from an Oz Jet Boating trip.

Aha, I think, that's in my Smartvisit guidebook! At the nearby booth, I sign up for the next outing. "You're going to get wet," the captain grins. Twenty minutes later - as we spin under the harbour bridge - I open my mouth to scream and get a good gulp of salt.

Back onshore, I run to catch an Opera House tour, arriving soggy and late to the disapproval of a camp-as-Elton guide, who grudgingly allows me to tag along.

Over the next two days I scale the harbour bridge's Pylon Lookout, visit four museums, one zoo, and bus to Bondi Beach. When the airport beckons, I still haven't crossed off half the things in my guidebook. Next time, I'll give myself a week. Or maybe just move here.

* Air New Zealand offers daily flights from Auckland, Wellington and Christchurch to Sydney. Fares start ex-Auckland from $229 one way. For more information on flight, accommodation, travel insurance and rental vehicles call 0800 737 000 or visit an Air New Zealand Holidays Store.