Moroni is the capital of the Comoros, an island nation located in the Indian Ocean off the coast of East Africa. It has a population of around 690, 000 people and is the largest city in the country. Riga is the capital of Latvia, a country located in Northern Europe on the Baltic Sea. It has a population of around 700, 000 people and is the largest city in the country. Hanoi is the capital of Vietnam, a country located in Southeast Asia. It has a population of around 7.5 million people and is the second largest city in the country.