We are going to Vietnam and Cambodia in October. I have applied for a Visa on Arrival for Vietnam but am totally confused about Cambodia. Do they have a similar VOA or can I really get the visa when I arrive at the border? We are doing a Mekong Delta cruise to Phnom Penh, can we get one when we arrive. Do we need a letter as we do for our Vietnam Visa and if not what do we need??? Totally confused nothing seems clear and we don't want to get caught out..