Salzburg

Just off the Danang Beach coastal road, the Marble Mountains (Ngu Hanh Son) consist of five craggy marble outcrops topped with pagodas. Each mountain is named for the natural element it’s said to represent: Thuy Son (Water), Moc Son (Wood), Hoa Son (Fire), Kim Son (Metal or Gold) and Tho Son (Earth). The villages that have sprung up at the base of the mountains specialise in marble sculpture, though they now astutely use marble from China rather than hacking away at the mountains that bring the visitors in.

South of Hanoi, Ninh Binh province is blessed with natural beauty, cultural sights and the Cuc Phuong National Park. Highlights include boat trips amid karst landscapes at Tam Coc and the Unesco World Heritage-listed Trang An Grottoes.

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.

Set in an idyllic valley, hemmed in by hills, the Mai Chau area is a world away from Hanoi's hustle. The small town of Mai Chau itself is unappealing, but just outside the patchwork of rice fields rolls out, speckled by tiny Thai villages where visitors doss down for the night in traditional stilt houses and wake up to a rural soundtrack defined by gurgling irrigation streams and birdsong.

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.

Graceful, historic Hoi An is Vietnam’s most atmospheric and delightful town. Once a major port, it boasts the grand architecture and beguiling riverside setting that befits its heritage, and the 21st-century curses of traffic and pollution are almost entirely absent.

Once upon a time, Mui Ne was an isolated stretch of shoreline where pioneering travellers camped on the sand. Times have changed and it's now a string of beach resorts, which have fused into one long coastal strip. These resorts are, for the most part, mercifully low-rise and set amid pretty gardens by the sea. The original fishing village is still here, but tourists outnumber locals these days. There are a handful of luxury hotels (and a smattering of cheap guesthouses) but Mui Ne is mainly a midrange resort.

Ha Giang is the final frontier in northern Vietnam, an amazing landscape of limestone pinnacles and granite outcrops. The far north of the province has some of the most spectacular scenery in the country – if not the region – and the trip between Yen Minh and Dong Van, and then across the Mai Pi Leng Pass to Meo Vac, is quite mind-blowing. Ha Giang should be one of the most popular destinations in this region, but its distance from just about everywhere else keeps visitor numbers at a low level.

Cat Tien comprises an amazingly biodiverse area of lowland tropical rainforest. The 72,000-hectare park is one of the outstanding natural treasures in Vietnam, a true jungle, and the hiking, mountain biking and birdwatching here are the best in the south of the country. At weekends and public holidays it gets busy with domestic tourists – it's worth calling ahead to book the most popular excursions.

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.