The time of year has a major impact on flight prices. Starting out from Europe, North America or Australia, figure on prices rising dramatically over Christmas and between July and August, and dropping significantly during lax periods of business like February, June and October.
Thailand is the most convenient gateway to Cambodia when travelling from outside the region. In Bangkok, the Banglamphu area, especially Khao San Rd, is a good place to buy tickets to Cambodia. Those who are travelling into Cambodia by air through Vietnam can easily pick up tickets in Ho Chi Minh City.
When buying tickets in Cambodia, the biggest agents are in Phnom Penh, although many now operate branch offices in Siem Reap. Agents can normally save you a few dollars on the airline price, much more for long-haul flights or business-class seats
There is a river border crossing between Cambodia and Vietnam on the banks of the Mekong. There are regular fast passenger boats plying the route between Phnom Penh and Chau Doc in Vietnam, via the Kaam Samnor