Hoi An to Hanoi

Most travellers overlook the region, but there's plenty more to central Vietnam than Hoi An and Hue – and we've now got the trip to prove it. In addition to time spent in both of places, which are must-visits on any itinerary, this trip ventures where very few others do: up into the highlands of the Truong Son mountain range and underground in the Tu Lan Cave System just outside Phong Nha. Spend a night in the remote village of Bho Hoong, home of the ethnic Co Tu people, and learn about their traditional way of life. Then, after a couple of days exploring Hue's ancient citadel, get ready for something else completely different. Over two days and one night, venture below ground into one of the world's largest – and most recently discovered – cave complexes. Wind through narrow rock corridors, scramble along rocky outcrops, swim through subterranean rivers and camp in the jungle. Highlights/r/n

• Fall under the spell of enchanting Hoi An, an old port city of colonial-era architecture, superb dining and unrivalled shopping
• Learn the ways and history of the ethnic Co Tu people during an overnight stay in the highland village of Bho Hoong
• With its sprawling array of attractions, the imperial city of Hue is best explored from the back of a motorbike and cruising down the Perfume River by dragon boat
• Cruise around emerald karsts off the coast of Cat Ba Island
• Sample the literal life underground on a two-day spelunking adventure through the enormous caves and subterranean rivers of Tu Lan Cave system and Phong Nha