Dominant features are the large, almost centrally located, Tonle Sap ( Great Lake ) and the Mekong River, which traverses the country from north to south and is the 12th longest river in the world.

Except for the smaller rivers in the southeast, most of the major rivers and river systems in Cambodia drain into the Tonle Sap or into the Mekong River.

The Mekong River flows in from the northeast and the Tonle Sab — a river emanating from the Tonle Sap — flows in from the northwest.

The Mekong has thus not been an obstacle but a facilitator for communication, and the similarities between Laos and northeast Thai society — same people, same language — reflect the close contact that has existed across the river for centuries.

The Mekong River, which both sides have an interest in making a " river of true peace and friendship " — as their respective prime ministers called for in 1976 — also provides a north – south artery during the rainy season.

The Mekong river delta or Mekong delta, covering about 40, 000 square kilometers, is a low-level plain not more than three meters above sea level at any point and criss-crossed by a maze of canals and rivers.

At Phnom Penh it merges with the Tonle Sap and divides into two branches-the Sông Hậu Giang ( Hau Giang river ) ( known as the Bassac River on the Cambodian side ) and the Sông Tiền Giang ( Tien Giang river )-and continues through Cambodia and the Mekong basin before draining into the South China Sea through nine mouths known as the Cửu Long ( nine dragons ).

A tributary entering the river at Phnom Penh drains the Tonlé Sap, a shallow freshwater lake that acts as a natural reservoir to stabilize the flow of water through the lower Mekong.

The effect is to reduce significantly the danger of devastating floods in the Mekong delta, where the river floods the surrounding fields each year to a level of one to two meters.

The river region is characterised by fertile mountain valleys and includes the Yarlung Tsangpo River ( the upper courses of the Brahmaputra ) and its major tributary, the Nyang River, the Salween, the Yangtze, the Mekong, and the Yellow River.

The boundary of the gulf is defined by the line from Cape Bai Bung in southern Vietnam ( just south of the mouth of the Mekong river ) to the city Kota Baru on the Malaysian coast.

Luang Prabang, or Louangphrabang ( Lao: ຫ ຼ ວງພຣະບາງ, literally: " Royal Buddha Image ( in the Dispelling Fear mudra )," pronounced ), is a city located in north central Laos, at the confluence of the Nam Khan river and Mekong River about 425 km north of Vientiane.

Chaiyasetthathirath came under serious threat of attack after the Burmese took Chiang Saen, north-east of Chieng Mai, and Bayin-naung's forces gained the position to make an armed attack down the Mekong river.

The Mekong river crosses the province roughly through the center.

Bokeo's provincial capital is Houayxay on the Mekong river.

In November 1975, the Prince escaped from Laos by swimming across the Mekong river to Thailand.

The Mekong river forms the boundary with Laos, the Mae Sai and Ruak River to Burma.

First, the remaining Champa territories were taken ; next, the areas around the Mekong river were placed under Vietnamese control.

The province is located in the valley of the Mae Nam Kong ( Mekong river ), which also forms the border with Laos.

Khmer Krom or Southern Khmer is spoken by the indigenous Khmer population of the Mekong Delta, formerly controlled by the Khmer Empire but part of Vietnam since 1698.

To the southeast of this great basin is the Mekong Delta, which extends through Vietnam to the South China Sea.

Most of the western border of Laos is demarcated by the Mekong River, which is an important artery for transportation.

In the north, the country is bounded by a mountainous 423-kilometer border with China and shares the 235-kilometer-long Mekong River border with Burma.

As a landlocked country, Laos possesses no ports or harbours on the sea, and the difficulty of navigation on the Mekong means that this is also not a significant transport route.

Laos is connected across the Mekong to Thailand by First and Second Thai-Lao Friendship Bridges.

Laos is a member of the following international organizations: Agency for Cultural and Technical Cooperation ( ACCT ), Association of Southeast Asian NationsASEAN, ASEAN Free Trade Area ( AFTA ), ASEAN Regional Forum, Asian Development Bank, Colombo Plan, Economic and Social Commission for Asia and Pacific ( ESCAP ), Food and Agriculture Organization ( FAO ), Group of 77G-77, International Bank for Reconstruction and Development ( World Bank ), International Civil Aviation Organization ( ICAO ), International Development Association ( IDA ), International Fund for Agricultural Development ( IFAD ), International Finance Corporation ( IFC ), International Federation of Red Cross and Red Crescent Societies, International Labour Organization ( ILO ), International Monetary Fund ( IMF ), Intelsat ( nonsignatory user ), Interpol, International Olympic Commission ( IOC ), International Telecommunication UnionITU, Mekong Group, Non-Aligned Movement ( NAM ), Permanent Court of Arbitration ( PCA ), United Nations, United Nations Convention on Trade and Development ( UNCTAD ), United Nations Educational, Scientific and Cultural Organization ( UNESCO ), United Nations Industrial Development Organization ( UNIDO ), Universal Postal Union ( UPU ), World Federation of Trade Unions, World Health Organization ( WHO ), World Intellectual Property Organization ( WIPO ), World Meteorological Organization ( WMO ), World Tourism Organization, World Trade Organization ( observer ).

The original type of sushi, known today as nare-zushi () was first developed in Southeast Asia possibly along what is now known as the Mekong River and then spread to southern China before introduction to Japan.

The Northeastern part is drained by rivers flowing into the Mekong basin, like the Kok and Ing.

The well drained, loose sandy alluvium of the Mekong flood plain is very fertile, the main crops being tomatoes on an industrial scale, tobacco, and pineapples.

Demarcation is complete except for certain Mekong islets.

The border marked by the Mekong is as liquid as the waters within it: at high water during the rainy season, the centre line of the current is the border, while during low water periods, all islands, mudbanks, sandbanks, and rocks that are revealed, belong to Laos.

Ferry service between hundreds of islands and the mainland is available, as well as across navigable rivers, such as Chao Phraya and Mae Khong ( Mekong ).

The Red River Delta ( also known as the Sông Hồng ), is a flat, triangular region of 15, 000 square kilometers, is smaller but more intensely developed and more densely populated than the Mekong River Delta.

The Mekong, which is 4, 220 kilometers long, is one of the 12 great rivers of the world.

The climate in the southern regions especially Ho Chi Minh City and surrounding Mekong Delta is predominantly Tropical savanna climate with high humidity and a distinct wet and dry season.

Although the Mekong was established as a border by French colonial forces, travel from one side to the other has been significantly limited only since the establishment of the Lao People's Democratic Republic ( LPDR, or Laos ) in 1975.

The pulsing system with its large floodplain, rich biodiversity, and high annual sediment and nutrient fluxes from Mekong makes the Tonlé Sap one of the most productive inland fisheries in the world, supporting over three million people and providing over 75 % of Cambodia's annual inland fish catch and 60 % of Cambodians ' protein intake.

In one version, related by a CPK cadre from Kampong Cham, Yuon was said to have been shot in August 1975 by a group of Khmer Rouge soldiers after he sympathetically addressed a group of evacuees at Prek Por, Srey Santhor District, and his body thrown into the Mekong.

Nam Ngum, the largest river in the province originates from the mountains in Paek District and is one of the major tributaries of the Mekong.

Due to the successes of Operation Market Time and Operation Game Warden ; one of the few places left for the North Vietnamese to smuggle troops and supplies into the Mekong Delta was through the rivers, canals and lakes that were near the Cambodian border.

It is one of the country's southern provinces, being situated in the delta of the Mekong River.

Geographically, Bến Tre is wedged between the two main branches of the Tiền Giang River, which is itself one of the two main branches of the Mekong.

Marie-Thérèse Nguyễn Hữu Thị Lan was born in Gò Công, a Mekong Delta town in what was then the French colony of Cochinchina, one of the three areas ( the others being the protectorates of Annam and Tonkin ) that composed the Union of French Indochina.

In July 2003, MRC CEO Joern Kristensen reported that China had agreed to scale back its plans to blast rapids by implementing only phase one ( of three ) of its Upper Mekong Navigation Improvement Project ; however, China ’ s future intentions in this area are far from certain.

The Tha River ( Nam Tha ) is a river in northwest Laos, and one of the 12 tributaries on the Mekong River.

Unable to reach the system before the Mekong overtakes him, he travels towards one of Parada IV's moons and manages to outmaneuver the other runabout, which assumes another course.