Capital or also sometimes called City of San Juan is a department of the province of San Juan, located in the south center of the same, in the northwest of the Tulum Valley, approximately in the center of the Cuyo region, to the west center from Argentina. This department has only 30 km², where a totally urban landscape is developed, in which more than 100 000 inhabitants reside, supported economically, in a majority way in tertiary activities of all kinds. Within its limits, the central business district of the City of San Juan is located, making it the institutional center, administrator, manager as well as in the seat of the governmental authorities of the named province.
Capital stands out for being the only department of San Juan to have a surface, in complete form, constituted by urban landscape where agricultural activities are non-existent. It is also the only political unit that constantly presents a decrease in its population, caused by a population exodus to areas of lower building density in search of an ecologically more viable space for residence.