Registered in 1995, Ream National Park has so far achieved a rare feat: thanks to vigilant, apparently uncorrupt rangers, they've managed to keep most of Ream's mangroves, wildlife and beaches in pristine condition. The park's 200 inhabitants have not been forcibly relocated (unlike similar schemes in Thailand) but have been allowed to stay and continue their subsistence fishing lifestyle. No new residents are allowed, keeping Ream's ecosystem in reasonable balance.

The Cambodian navy has a base at Ream, and sailors may appear unexpectedly; usually they're doing little more than cooking their lunch. The park has landscapes for anyone: mangrove forests, a mountainside waterfall, and miles of beaches unmarked by footprints. Nearly 200 bird species live here, including herons and cranes. King cobras and pythons have been spotted, too, so be vigilant on hiking trails!

Though there are plenty of trips offered by travel agents in Sihanoukville, it's easy enough to get there on your own, either with a motodop or by renting a motorbike. There are 35 rangers in Ream park, and several speak english. Trekking with a ranger's advisable when in Ream: their services are reasonable, at $2/hour. Hikes to meditation mountain and Keng Kong waterfall are popular trips. Another excellent option is a boat trip down the mangrove-lined Prek Toeuk Sap river, done with a group of other travellers. For 1-5 people it's $35, and for 6 or more the going rate is $6 each. The Prek Toeuk Sap Freshwater River is salty in the dry season as seawater flows inland, and filled with freshwater from ponds in the rainy season. Flying fish cartwheel out of the water, and dolphin sightings are not uncommon.

There's little food or drinking water available in the park, so if planning a hike or an overnight trip, ensure you have enough of your own. Basic accommodation is available at Ream, as well, and some travellers like it so much here they decide to come back for a night or two.