It should be better 9 to 28 days for Vietnam and Cambodia trip package. You will have chances to experience both stunning Nature UNESCO Heritage Sites in Vietnam and UNESCO Cultural Heritage Sites in Vietnam and Cambodia.
The high mountains in North Vietnam offer breathtaking scenery such as Puluong, Maichau, Mu Cang Chai, Lai Chau Dien Bien, Sapa, Y Ty, Hoang Su Phi, Hagiang, Bangioc water fall, Babe lake. These places are great for those who want to get away from the city life and get soaked with stunning scenery and low space of life.
A. Short Tours of Vietnam and Cambodia from 9 days - 10 days: You should visit Angkor Wat & Northern Vietnam with Halong bay, Ninhbinh & Sapa
B. 11-day Tours of Vietnam and Cambodia: You should visit Angkor Wat & Central, Northern Vietnam with Halong bay & Sapa, Hoian
C. 12-day Tours of Vietnam and Cambodia: You should visit Angkor Wat & Central, Northern Vietnam with Halong bay, Ninhbinh & Sapa, Hoian
C. 13 & 14-day Tours of Vietnam and Cambodia: You should visit Angkor Wat & South, Central, Northern Vietnam
D. 15 & 21-day Tours of Vietnam and Cambodia: You should visit Phnom Penh, Angkor Wat & South, Central, Northern Vietnam