Eco-tourism is a combination of two words _ ecology and tourism. Eco-tourism means travel to natural areas, specifically to seek understanding of the culture and history of the environment, taking care not to alter the integrity of the ecosystem while producing economic opportunities that ensure the conservation of natural resources beneficial to local people. Eco-tourism is the most common reason for travel to to natural wonders such as the Tonle Sap Lake region, or national parks. The Ministry of Tourism defines natural features that attract eco-tourists as striking scenery, and special features such as waterfalls, caves or mountain ranges or unusual eco-systems and their flora and fauna.. Nature tourism can take many forms. Eco-tourism is nature tourism that particularly focuses on conservation of the natural environment and local cultures, and tourists learn about nature and related cultures. Local field studies are to be carried out in selected areas in various provinces throughout Cambodia. National parks and reserves including the southwest cluster of the Kirirom Mountains in Kampong Speu, Bokor Mountain and Kep National Park in Kampot Province and Ream National Park in Sihanoukville are to be studied. Cambodia is home to important forest and marine eco-systems as well as many endangered animal species. In Cambodia, domestic and international tourists can visit historical and cultural destinations, but there is also much potential for eco-tourism and other sustainable development activities in most provinces.