Jump on the Reunification Express train that links north to south and hop off to cycle around the imperial temples of the ancient citadel of Hue. Cycle around the beautiful and compact port town of Hoi An, an ancient Chinese trading post and eat delicious fish cooked in banana leaf for lunch.
Further south as the temperature rises the palm-fringed beaches become more inviting, particularly if you have been working up a sweat biking in the Central Highlands on some steep ascents and exhilarating descents. Nha Trang offers a good break from the bike as you can take a boat trip to tropical islands for snorkelling and swimming.
The southern city of Old Saigon or Ho Chi Minh City contrasts nicely with Hanoi and from here you can ride out to the Cu Chi Tunnels complex of underground tunnels and bunkers, where thousands of Viet Cong troops hid and fought a war on the doorstep of the Americans.
Further south the Mekong Delta region is another world where life unfolds on and around the river. Ride your bike across the Delta, combining boats and bridges to learn how the locals have adapted to life in the Delta.