This is the long version of central Vietnam, and the extra days show. You start in Hoi An with a choice between a lantern-making village and a herbal foot soak, then spend a full morning in the old town rather than an hour of it: Tan Ky Old House, the Japanese Covered Bridge, the Fukian Assembly Hall from 1690 and the market along the Thu Bon.
From there the trip opens out. A day at Ba Na Hills and the Golden Bridge, a speedboat to Cham Island for snorkelling water and a seafood lunch, then two days in Hue for the Imperial Citadel, Khai Dinh's mausoleum and Thien Mu Pagoda, with an evening of Hue folk singing on the river.
The last stretch comes back down to Da Nang through Dong Ba Market, ending at the Dragon Bridge on a night it breathes fire.