Cambodia is a Southeast Asian country that covers an area of 181,035 square kilometers. It has a long coastline along the Gulf of Thailand and borders Thailand, Laos, and Vietnam. The country's geography is dominated by the low-lying central plain, which includes the Tonlé Sap lake and the Mekong river. The plain is surrounded by mountain ranges, such as the Cardamom Mountains in the southwest and the Dangrek Mountains in the north. 

Cambodia can be divided into four main geographical regions: The Northwestern, The Eastern, The Mekong Lowlands and The Cardomom and Elephant Moutains.

1. The Northwestern Region:

The northwestern region of Cambodia is a fascinating area that offers a glimpse into the ancient and modern history of the country. It borders Thailand and Laos, and covers several provinces, including Banteay Meanchey, Oddar Meanchey, Preah Vihear, Siem Reap, and Battambang.

This region is home to some of the most impressive and remote temples in Cambodia, such as Prasat Preah Vihear, a UNESCO World Heritage Site perched on a cliff overlooking the Cambodian-Thai border, and Banteay Chhmar, a sprawling complex surrounded by jungle and partially collapsed by time and war. It also boasts natural attractions, such as the Tonlé Sap lake, the largest freshwater lake in Southeast Asia and a vital source of fish and livelihood for millions of Cambodians. The lake hosts diverse ecosystems and floating villages that can be explored by boat.

The northwestern region of Cambodia is also known for its cultural heritage and artistic expression, especially in Battambang, the second-largest city in the country and a hub for contemporary art and architecture. The city has a charming colonial-era atmosphere, with French-style buildings and tree-lined streets. It also has a vibrant arts scene, with galleries, museums, and studios showcasing local talent. Battambang is also famous for its bamboo train, a unique and fun way to travel through the countryside on a bamboo platform powered by a small engine. Northwestern region is a rich and diverse area that offers something for everyone, from ancient temples and natural wonders to modern art and culture.

2. The Eastern Region:

The eastern region of Cambodia is part of the Eastern Highlands, a mountainous area that covers parts of Cambodia, Laos and Vietnam. It is characterized by rugged terrain, dense forests and rich biodiversity. The region is home to several ethnic minority groups, such as the Jarai, Stieng, Brao and Krung, who have their own languages and cultures. 

The eastern region also has some of the most important natural resources in Cambodia, such as rubber, timber, gemstones and hydropower. However, it faces many challenges, such as deforestation, land degradation, illegal logging and mining, and lack of infrastructure and development. The region also suffers from the legacy of the Vietnam War and the Khmer Rouge regime, which left behind many landmines and unexploded ordnance. 

Overall, eastern region of Cambodia is an area of great potential and diversity, but also of great vulnerability and conflict.

3. The Mekong Lowlands:

The Mekong lowlands region of Cambodia is a part of the larger Tonle Sap Basin and Mekong Lowlands, which covers most of the central and southern parts of the country. This region is characterized by flat and fertile plains that are nourished by the Mekong river and its tributaries, such as the Bassac and the Sab rivers. The river enters Cambodia from Laos at the Khone Falls and flows southward to the border with Vietnam, forming part of the international boundary between the two countries. It is also connected to the Tonle Sap lake, the largest freshwater lake in Southeast Asia, by the Sab river. 

The Tonle Sap lake plays a vital role in regulating the water level and fishery resources of the Mekong river system. The Mekong lowlands region of Cambodia is home to most of the country's population and economic activities, including agriculture, fisheries, tourism, and industry. It also hosts the capital city of Phnom Penh, which lies at the confluence of the Mekong and Tonle Sap rivers. The region faces several challenges, such as environmental degradation, flooding, drought, climate change, and urbanization. These factors affect the livelihoods and well-being of millions of people who depend on the natural resources and services provided by the Mekong river and its basin.

4. The Cardomom and Elephant Moutains:

The Cardamom and Elephant Mountains are two mountain ranges in the south-west of Cambodia, extending from the Gulf of Thailand to the central Cambodian plain. They are part of the biodiversity hotspot of Indo-Burma and home to many endangered species of flora and fauna. The Cardamom Mountains are the larger and higher range, with peaks reaching over 1,700 meters above sea level. The Elephant Mountains are a lower and narrower range, named after their resemblance to a herd of elephants. Both ranges are covered by dense tropical rainforest on their western slopes, where they receive abundant rainfall from the monsoon winds. On their eastern slopes, however, the climate is drier and the vegetation is less lush.

The Cardamom and Elephant Mountains have a rich and diverse cultural heritage, as they have been inhabited by various ethnic groups over the centuries. The most prominent are the Khmer, who have left behind many historical sites, such as temples, palaces and jar burials. The jar burials are a unique type of funeral practice, where ceramic jars and wooden coffins are placed on natural rock ledges in remote locations. The mountains also host several indigenous communities, such as the Pear, Chong and Suoy, who have their own languages, traditions and beliefs. The mountains have also been a refuge for political dissidents and rebels during times of conflict and turmoil in Cambodia's history.

The Cardamom and Elephant Mountains offer many opportunities for adventure and ecotourism, as they boast some of the most scenic and pristine landscapes in Cambodia. The mountains are ideal for hiking, trekking, camping, birdwatching and wildlife spotting. Some of the attractions include waterfalls, caves, rivers, lakes and hot springs. The mountains also have several protected areas, such as national parks and wildlife sanctuaries, where visitors can observe rare and endangered animals, such as elephants, tigers, leopards, bears and gibbons. The mountains are also close to some of Cambodia's most popular coastal destinations, such as Sihanoukville, Kampot and Kep.