Kirirom National Park
"Kirirom offers some stellar mountain biking and, so I am told, bouldering. There are countless trails winding every which way – north through the Southern Cardamoms, east toward Cambodia’s highest peak (Phnom Aoral), and west toward the Elephant Mountains. Birds, squirrels and Buddhist monks saunter around the lake at the top of the mountain, setting the scene for a peaceful campsite at the end of a day exploring various trails."

Kirirom National Park is a national park in Cambodia. It was Cambodia's first officially designated national park. It is located mostly in Phnom Sruoch District, Kampong Speu Province, while a smaller section is in neighboring Koh Kong Province.
The meaning of "Kirirom" is "Happy Mountain". This name was given to the area by King Monivong in the 1930s. The ancient name of the place was Phnom Vorvong Sorvong for the main two hills, which are connected with the Cambodian popular legend about two heroic princely brothers, Vorvong and Sorvong.
The park extends over the eastern part of the Cardamom Mountains. Only two hours from Phnom Penh. Kirirom is national park on the road between Sihanoukville and Phnom Penh, on route for anyone coming to Cambodia from Thailand at the Koh Kong crossing.
The park, 90km south of Phnom Penh, can be reached by public transport, though with some difficulty and plenty of time. From Sihanoukville, you can get minibus or shared taxi to Trang Tro Yeung. Kirirom is national park on the road between Sihanoukville and Phnom Penh, on route for anyone coming to Cambodia from Thailand at the Koh Kong crossing.

From the highway it's 10km on a sealed road to a small village near the park entrance. From the village you have two choices: the left fork takes you 50m to the park entrance and then 17km up a fairly steep sealed road to the unmanned Kirirom Information Centre inside the park proper;
the right fork takes you 10km along the perimeter of the park on a dirt road to Chambok commune, site of an excellent community based ecotourism (CBET) program. These are two vastly different experiences, and they are nowhere near each other, so it's recommended to devote a day to each.
The Unique of Natural Beautiful scenery pine forest, astonishing waterfalls and a home to many endangered species of animal. There are popular picnic spots and wide of variety leisure activities on the Mountain. It contains many footpaths through the forests with a number of small lakes and waterfalls and was once used as a refuge by the Khmer Rouge. In the park live the Asian Elephant, Deer, Wild Ox Gaur, Wild Ox Banteng, Leopard, Spotted Linsang, Pileated Gibbon and Tiger.
In the park you can do: Bird Watching, Hiking, Ox-cart Riding, Picnicking, Trekking. Bathing at the stream, Fishing, Canoeing, Horse Riding and Boating.