Darwin: The modern capital of Australia's Top End

This is our parliament building, affectionately known as The Wedding Cake," says owner/driver Matt as we approach an arrestingly white edifice with rows of symmetrical columns. "It's white and square and full of fruits, nuts and alcohol."

Matt's lighthearted introduction to the Northern Territory's multicultural capital city with a laid back tropical lifestyle comes at the start of his three-hour Double Decker Tour. The open-top bus runs daily sightseeing tours, which Matt advertises as the best way to get familiar with the city, "because seeing things topless is much more fun".

I'm visiting Darwin at the end of a six-day cruise from Brisbane, on Queen Mary 2, part of a circumnavigation of Australia by the Cunard cruise liner. It has been a joy and privilege to sail on the QM2, as she is affectionately called. On my cruise she has well and truly lived up to her reputation as the finest liner afloat, being so smooth and silent I could not tell whether the vessel was under way without going to the rail and looking at the ocean.

Our bus tour leaves from the eye-catching Darwin Visitor Information Centre, a short stroll from the wharf. Rain threatens but Matt issues ponchos to his top-deck guests and promises the imminent "liquid sunshine" won't rain on his parade.

His next words of wisdom alert us to the presence of saltwater crocodiles. The fearsome reptiles lurk in the shallows in the torrid May-October Dry Season, when there is uninterrupted sunshine and visitors may long for a dip in the ocean.

Poisonous jellyfish make the harbour off-limits in the wet season, when dazzling lightning storms sweep over the city. Fortunately, there are places to enjoy a swim, the most popular within Darwin Waterfront Precinct, a new destination for anyone who wants to cool off in the aquamarine Recreation Lagoon, ride a boogie board on 1.7m breakers in the Wave Pool, have a picnic or meet friends. It's the perfect retreat from tropical heat. Matt encourages guests to visit Crocodylus Park, where 10,000 crocs, snakes, lions, tigers and Australian fauna compete for TLC from their devoted handlers. There's a nifty protective cage, where the enigmatic smile on the crocodile can be seen at close quarters through steel bars.

As we drive down Mitchell St, the main drag, where shopping arcades, cinemas, cafes and restaurants back the busy pavements, our driver assures us, "I want to make you feel like locals on this tour".

I begin to see what he means. The city is compact and homely, in complete contrast to the big bustling capitals in other states. Once renowned for its hard-bitten, rough and ready frontier atmosphere, Darwin now has a modern, cosmopolitan outlook, completely rebuilt after devastating bombing raids in 1942 and Cyclone Tracey in 1974.

As we rumble past the Chinese Temple and Indonesian Consulate, Matt tells us that this culturally diverse city of around 60 nationalities was first settled by Aborigines 40,000 years ago and by Europeans in 1824. It was named Port Darwin after the evolutionist Charles Darwin, though he never visited the port.

On the Esplanade we pass Government House, where the first female Northern Territory Administrator, the Hon. Sally Thomas, resides. Further along we come to Aquascene in Doctors Gully, where 8m-high tides bring fish to shore for hand-feeding. Hundreds of mullet, catfish, bream and barramundi come barrelling in to feed while people wade in among the real Aussie ankle-biters with their offerings.

The mirror-smooth tranquillity of Cullen Bay Marina captivates me immediately. It's a place to relax and enjoy fresh seafood, pasta, succulent steak, Greek mezze and Thai cuisine. The bay offers fish, dive and cruise charters, with access to the sea via a two-stage lock system.

Douglas, our double-decker, motors along to Mindil Beach, a Dry Season venue for Thursday and Sunday sunset markets under the palm trees.

Darwin's favourite meeting place is always crowded on market days with craftspeople, bush tucker vendors, buskers and bands. It's a place to bring the family and enjoy the local lifestyle.

The notorious old penal institution of Fannie Bay Gaol looms up. It's a jumble of corrugated iron and wire netting with a chilling gallows section. Matt points out that in addition to Fannie Bay, the Top End has other fanciful place names like Humpty Doo, Rum Jungle and Bachelor.

Our bus disgorges us at the Museum & Art Gallery, the Territory's premier cultural institution. It's easy to spend an hour or two browsing through the fine art collection, the Aborigine bark paintings and the Cyclone Tracey exhibition. I'm drawn to the snaggle-toothed jaws of the formidable five-metre saltwater crocodile called Sweetheart, which gained notoriety in the 1970s through his annoying habit of seizing outboard motors in his jaws.

At the end of the bus tour I stroll through Darwin Mall and meet a local called Tickles, who likes to be handled. At least that's what his weathered handler claims as he drops the 2m-long black-headed python into my arms. Tickles is more at home hunting and devouring poisonous king brown snakes, being immune to their toxins. His jaws unlock and open like a trumpet enabling him to swallow a full-grown wallaby. Darwin is full of surprises like this. I find the locals relaxed and friendly. The city is vibrant with a "no worries" attitude. There's diverse cuisine, bright festivals, buzzing markets, all enhanced by vivid bougainvillea, frangipani, acacia, poinsettia and flame trees.

Paul Rush travelled to Darwin courtesy of Cunard Line and Crowne Plaza Hotel.