Seven or eight kilometres outside of Koh Kong city, or Krong Koh Kong, in Cambodia is an enormous mangrove forest where visitors can observe the delicate ecosystem that locals (and probably an NGO or two) have turned into a thriving ecotourism project.
Part of the nearly 25,000-hectare Peam Krasop Wildlife Sanctuary, the Boeng Kayak area has a kilometre-long mangrove walk, with elevated cement and wooden platforms snaking through the mangrove forest. Entrance fees (5,000 riel for foreigners, 3,000 for Cambodians) go towards supporting the project, which aims to provide local villagers with alternatives to ecologically damaging choices.
The mangrove forests of Cambodia are environmentally important, providing homes to hundreds of species of wildlife, including, it's said, the famous Irrawaddy dolphins, a pug-nosed species related to the killer whale which are endangered due to the destruction of their natural habitat. (The dolphins are often visited by tourists in their habitat 20 km outside the Cambodian town of Kratie.)
Koh Kong province's mangrove forests have been deteriorating since 1979, when the Khmer Rouge were overthrown. At that time, Koh Kong was sparsely populated, and many of the newly displaced Cambodian population chose to make Koh Kong home. The bridge from Thailand and the sealing of roads to the capital have only served to increase the population further, and more fishing and charcoal production has put enormous pressure on the mangroves and their ecosystem.
Supporting the locals in alternative occupations, such as tourism, can help save Cambodia's mangroves. In addition to the mangrove walk -- which, incidentally contains what might be the world's only public mangrove toilet -- visitors can hire boats to birdwatch among the mangroves. There's also a "resort" and restaurant set up, with a dozen or so air-conditioned bungalows for those who want to spend the night watching the fireflies in the mangroves (though since when is air-con environmentally friendly?) The easiest way to visit is to organise the journey from Krong Koh Kong, where you can hire a moto to take you there.