Northwestern Cambodia is a region of Cambodia and includes the provinces of Banteay Meanchey, Oddar Meanchey, Preah Vihear, Siem Reap and the part of Stoeng Treng to the west of the Mekong.
The region's north is hemmed in by the Dangrek Mountains which form a natural barrier with Thailand. To the south is very flat and fertile land which leads towards the great Tonle Sap Lake.
Control of much of this area has often passed between the various regional powers. It is now part of Cambodia thanks to the French, whose sabre rattling forced the Siamese into relinquishing it (along with Battambang) in 1907. The region had been Siamese since 1867, thanks again to the French who gave it (and Battambang) to Siam in exchange for unobstructed French control over the remainder of Cambodia. Before then, a nominally independent Cambodia existed as a vassal state of Siam and Vietnam.
Siem Reap is by far the largest city, Sisophon and Poipet are small towns and Anlong Veng just feels like a large village.
Much of northwestern Cambodia is characterized by poverty. Siem Reap Province is one of the poorest in the country, despite its valuable temples. Infrastructure construction has been booming, though only since around 2008. This makes many older reported journey times and maps outdated. Outside the towns, car batteries provide expensive electricity to village homes.
For now, development means only the blazing of asphalt trails through remote areas. The growth of businesses and expanded tourism will surely follow, so explore off the tourist trail to get an insight into Cambodian life.
The region is served by Siem Reap-Angkor International Airport (IATA: REP) which has frequent domestic flights from Phnom Penh and is linked to the following destinations:
The following roads are all paved:
Hydrofoils ply the route across the Tonle Sap Lake from Phnom Penh to Siem Reap (6 hr), stopping stopping at Kampong Chhnang, US$20-25/person.
One boat daily runs between Siem Reap and Battambang in the Cardamom and Elephant Mountains region (5-8 hr, depending on the water level, boats can become grounded in the dry season).
If you're only making your way between towns in the region, then the days of rough, impassable roads and adventure are over. Most main routes are now paved, with the exception of only a few.
There is a range of bus companies serving all towns large enough to be worth visiting. The larger the town, the more regular the service.
Where the bus companies don't go, one should usually be able to travel by taxi. For the best chance of success, organise your taxi the night before, otherwise an early start may be needed to secure a place in a share-taxi.
It's not as simple to organize a pick-up truck as it is a taxi, but they have a different target market. Used for passengers and cargo, pick-up trucks head everywhere, providing a broad network, linking most every lonely village. If it weren't for these banged up wagons, most of the region wouldn't have access to affordable transport. Simply stand on the edge of the road, and flag the first one down.
Short trips outside towns can be made by hitching a ride on a slow, rustic, local tractor. Just flag down the first one heading your way. This is effectively hitch hiking, and comes with the usual dangers. US$0.75 per 15 km would be appropriate.
Siem Reap hosts a vast array of things to do beyond its temples. Ride horses, elephants, jeeps. Visit museums. Take cookery classes. Shoot things. Watch apsara dances. Get massaged. Take a boat on the Tonle Sap. Learn Khmer.
Outside Siem Reap the main pastime is marveling at being in the middle of nowhere (much of Cambodia's development is focused on its southeast): watch rice fields being burnt, planted, harvested. Stare at starry skies away from city light pollution.
Siem Reap hosts the region's gastronomic centre. All tastes and budgets are catered for. Elsewhere it's the usual provincial fare of soups, fruit, rice, meat, and veg.
Similar to the dining scene. Dry martinis can only be found in Siem Reap and the casinos near the border crossings. Every two-bit hut will serve cold water, cola and beer; local style coffee (cold and sweet) can be found just about everywhere.
Three of Cambodia's six overland crossings with Thailand are in this region:
Battambang, the main city of the Cardamom and Elephant Mountains region is 3-4 hr away from Siem Reap by bus or a trip on a boat.
The Mekong Lowlands and Central Plains are best reached on Hwy 6. The first major town in that region is Kampong Thom.
Cambodia's rugged east is best reached via Kampong Thom. The hardy should be able to cross the Mekong directly from the northwestern region to Stung Treng on a trip via Tbeng Meanchey.