For most visitors, this region is all about the enigmatic Cambodian capital, Phnom Penh, a chaotic crossroads of Asia's past, present and future. If you can pull yourself away from the poolside or escape the lively bars, then exploring the sights around the capital will reward.
The beautiful Mekong island of Koh Dach is the easiest trip to undertake and is best done by mountain bike or local transport. Udong, once the stupa-studded capital of Cambodia, is a half-day trip and can be combined with a visit to Kompong Chhnang.
The Angkorian temple of Tonlé Bati and the hilltop pagoda of Phnom Chisor are located near NH2 towards Takeo and can be combined with the excellent Phnom Tamao Wildlife Rescue Centre, where some behind-the-scenes tours get visitors closer to the animals.
Kirirom National Park, the closest protected area to Phnom Penh, en route to Sihanoukville, offers cool climes amid the pines.