Hue is a port city in central Vietnam, located on the banks of the Perfume River. It is the former imperial capital of Vietnam and is known for its historic monuments and architecture. Haiphong is a major port city in northern Vietnam, located on the coast of the Gulf of Tonkin. It is the third largest city in the country and is an important industrial center. Danang is a port city in central Vietnam, located on the South China Sea. It is the third largest city in the country and is a popular tourist destination. All three cities are important Vietnamese ports.