Da Nang or Danang is the fifth-largest city in Vietnam by municipal population. It lies on the coast of the South China Sea of Vietnam at t…Da Nang or Danang is the fifth-largest city in Vietnam by municipal population. It lies on the coast of the South China Sea of Vietnam at the mouth of the Hàn River, and is one of Vietnam's most important port cities. As one of the country's five direct-controlled municipalities, it falls under the administration of the central government.