Two weeks: the classic north-to-south

Days 1-3: Hanoi (Old Quarter, Temple of Literature, day trip to Ninh Binh's Trang An). Days 4-5: Ha Long Bay overnight cruise. Days 6-8: Sapa or the Ha Giang Loop. Days 9-10: fly to Hue, then the Hai Van Pass to Hoi An. Days 11-12: Hoi An (old town, beach, My Son). Days 13-14: fly to Ho Chi Minh City, Cu Chi tunnels, and a Mekong Delta day trip.

One week: pick a half

North in a week: Hanoi (3), Ha Long Bay (2), Ninh Binh (1), Sapa (2, tight). South in a week: Ho Chi Minh City (3), Mekong Delta (2), Phu Quoc or Con Dao (2).

Ten days: the food route

Hanoi (pho, bun cha, egg coffee), Hue (bun bo Hue, imperial banquets), Hoi An (cao lau, white rose), Saigon (com tam, banh mi, hu tieu). Travel by train and sleeper bus between meals.