For 10 points, name this large river of southeast Asia whose delta is in Vietnam.
One tributary of this river drains the Khorat Plateau. That tributary is the Mun. The Khone Falls blocks prevents navigating this river into one country. The Za Qu River is its primary source. This river is home to an exceptionally large species of giant catfish. Tonlé Sap drains into this river. Phnom Penh is located along this river which makes up the border between Thailand and Laos. For 10 points, name this large river of southeast Asia whose delta is in Vietnam.
One tributary of this river drains the Khorat Plateau. That tributary is the Mun.
{Mekong} River