Sector 3 (Sectorul 3 in Romanian) is an administrative unit of Bucharest. It is the most populous, most densely populated and also the third-largest division of the city. Actually, at its total population of over 460 thousand, it is the second-most populated administrative area of Romania, only after the capital city. It is also the most important of all six sectors of Bucharest, as it includes the Downtown Bucharest, the Kilometre Zero and other significant landmarks.