The region houses almost three quarters of Costa Ricans, and includes the capital and most populous city, San José.

A smaller range, the Carpintera Hills, which runs from north to south roughly along the border between the provinces of San José and Cartago, divides the valley into two sections.

The western part of the valley is influenced by trade winds in summer, and, as the rest of the country with the exception of the Caribbean region, there are two climate seasons clearly defined, wet and dry.

The Central Valley had been traditionally the favorite place for Costa Ricans to live, and even today it contains an unequal distribution of population of the country, in relation to its size.

The Greater Metropolitan Area (GAM) is the main populated conurbation of the country, and covers an extension roughly the same as the Central Valley.