Salzburg

Designated a Unesco World Heritage Site in 2003, the remarkable Phong Nha-Ke Bang National Park contains the oldest karst mountains in Asia, formed approximately 400 million years ago. Riddled with hundreds of cave systems – many of extraordinary scale and length – and spectacular underground rivers, Phong Nha is a speleologists’ heaven on earth.

Most of the bases and bunkers have long vanished, but this 5km strip of land on either side of the Ben Hai River is still known by its American War moniker: the DMZ. From 1954 to 1975 it acted as a buffer between the North and the South. Ironically, the DMZ became one of the most militarised areas in the world, forming what Time magazine called ‘a running sore’.

The spectacular karst limestone landscapes around Ninh Binh and Tam Coc are ideal for exploring by boat or bicycle, and there are stellar opportunities for caving and trekking amid the fast-developing travellers' scene of the Phong Nha-Ke Bang National Park. Dong Hoi, the coastal gateway to Phong Nha, also has an enjoyable low-key beach scene and good restaurants.

Notable for its extensive mangrove forest, Can Gio is a low, palm-fringed island sitting at the mouth of the Saigon River, some 25km southeast of Ho Chi Minh City. It was formed from silt washing downstream from the river, so don’t expect any white-sand beaches. A few hopeful resorts have sprung up along the murky 10km shoreline.

The bustling port city of Phan Thiet is traditionally known for its nuoc mam (fish sauce), producing millions of liters of the stuff per annum. There's not much to see in town, but the riverside fishing harbor is always chock-a-block with brightly-painted boats and there are sights nearby including the Ke Ga lighthouse and Ta Cu Mountain.

Towering limestone pillars and tiny islets topped by forest rise from the emerald waters of the Gulf of Tonkin. Designated a World Heritage Site in 1994, Halong Bay's scatter of islands, dotted with wind- and wave-eroded grottoes, is a vision of ethereal beauty and, unsurprisingly, northern Vietnam's number one-tourism hub.

Dong Van is the Ha Giang region's most popular overnight stop and, not coincidentally, is home to some solid accommodation and food. But the real reason to come is for the Sunday market, one of the region's biggest and most colourful. The town is also a good base for day treks around nearby minority villages and nearby sights such as the Lung Cu flag tower and the Lung Cam Cultural Tourist Village.

Gateway to the Mekong Delta, My Tho is the capital of Tien Giang province and an important market town – although for the famous floating markets, you’ll need to continue on to Can Tho.

Sleepy Bac Ha wakes up for the riot of color and commerce that is its Sunday market, when the lanes fill with villagers who flock in from the hills and valleys. Once the barter, buy and sell is done and the day-tripper tourist buses from Sapa have left, the town rolls over and goes back to bed for the rest of the week.

Heading east of Hoi An, new housing and hotels mix with older rice paddies, and the riverbank meanders for around 5km to sandy beaches. This palm-fringed coastline extends north to Danang, and despite the development, there are still a few quieter stretches; it's a good area to explore independently on two wheels.