Moscow is designated as a city.
A capital city ( or simply capital ) is the municipality exercising primary status in a country , state , province , or other region , usually as its seat of government . Moscow . The city is served by a transit network , which includes four international airports , nine railway terminals , numerous trams , a monorail system and one of the deepest underground rapid transit systems in the world , the Moscow Metro , the fourth-largest in the world and largest outside of Asia in terms of passenger numbers , and the busiest in Europe .