How long for Halong?

Our guide, Si, is recounting the local dragon legend. "The mother dragon and her children descended from heaven to help the Vietnamese fight off invaders from the north. They spat jewels and pearls that turned into islets ahead of the invading ships and sunk them. Following the victory they decided to stay and became Halong Bay and the karst rock formations strewn throughout the waterway. To this day, dragons are portrayed with pearls in their mouths."

Si tells the tale as we admire a dragon boat at the modern Quang Minh museum. Halong translates as "where the dragon descends (into the sea)", and it seems entirely appropriate that such extravagant folklore is used to explain its heavenly natural beauty. With his slick haircut and head-to-toe black outfit, Si is more Halong-hipster than traditional tour guide but his energy and knowledge bring the rich local culture to life. The entire second floor of Quang Minh is shaped like the inside hull of a boat and is dedicated to Halong's 4000-year-old seafaring heritage. The impressive two-year-old museum also venerates coal – a major source of the region's wealth - in a display bigger than that afforded to the "American War". The nature section explains the fascinating geology of the region and its flora and fauna. Giant clams, gaudy butterflies, enormous insects. Langurs and monkeys and cobras, oh my. Si explains the medicinal qualities of snake wine, the "undoubted" reason for his grandfather's rude health.

Si escorts us around the corner to the fishing wharf, where old boats have returned from what seems a productive few days at sea. The noisy wharf is redolent with success and packed with fishers in gum boots and conical hats. The wharf is too small for all the boats to dock at once and rowers yell at each other as they ferry those anchored away from the wharf to and fro for a fare of 2000 dong (about 10 cents). Si tells us there are around 1000 fishers in Halong and it appears they are all here this morning. Much of the fresh catch is still fresh (alive) when we see it hours later in the seafood quarter of Halong Market.

Halong Bay hosts every type of craft from kayak and canoe to tanker and cruise ship. Many are tourist vessels winding their way through the striking karst rock formations that drip with foliage like mint ice cream melting on roughly cut chuoi chien (banana fritters). Some formations look like floating boulders, others are complete islands with beaches and internal lakes.

Everyone comes here to see the bay and many take extended cruises for days. For those staying on land, a day cruise is de rigueur and our six-hour outing is a hoot. A stridently raucous traditional Viet band gives way to muzak-style Bee Gees covers and finally Chinese rock "classics" as we feast on an excellent buffet lunch of grilled fish, chicken porridge, seabass sashimi, Ho Tay prawn cakes and spag bol.

All this is prologue for the awesome Sung Sot Cave on Bo Hon Island. The 100-step climb to the entrance is rewarded with a 10,000 square metre double chamber that could hold a thousand people under the 30-metre high ceiling. A 500-metre path guides us past gaudily-lit ponds and monumental stalagmites. Intricate stalactites hang precariously, dappled by sunlight seeping in from surface fissures. Wonderment is unanimous. There are other caves in Halong Bay but the sheer volume of Sung Sot is humbling.

The cruise makes another stop at Ti Top Island – named for a Russian cosmonaut for some reason –which is crammed full of mostly Chinese tourists. They form a sweaty, tightly packed ant-run of pilgrims up the 400 rough-hewn stone steps to the top and are rewarded with one of the best views in the bay.

Halong Bay is just as exquisitely picturesque from the air and our 25-minute sightseeing seaplane flight circles out over the remarkable expanse of blue, dotted with the aforementioned boulders and islands. From the air the ageless serenity of the bay is countered by the numerous construction sites on shore, most in the early stages of development. Fun parks, water parks, shopping malls, restaurant precincts and family entertainment areas are all either being built or on the drawing board. The goal is to make Halong the definitive holiday destination in Vietnam.

Halong city is divided into two parts connected by the enormous Bai Chay Bridge. You can take an elevator to the top of the bridge, which is neon-lit at night, as is the ferris wheel on top of adjacent Ba Deo hill. All this neon gives the area a vaguely Vegas-lite look. You can take a cable car across the bay and ride the ferris wheel for US$15, all-inclusive.