The city hall is located in Old San Juan, in front of the Plaza de Armas and next to the Antiguo Palacio de la Real Intendencia (Palace of the Royal Intendancy), which today hosts the Puerto Rico Department of State.

Its current structure and façade by the square, inspired by the Casa de la Panadería in the Plaza Mayor of Madrid, completed in 1840 and was designed by architect Pedro García.

The Plaza de Armas main entrance has an inscription in Latin which translates to "Esteem the light of justice whoever is at the service of their people".

One of its most famous rooms is the Sala Capitular (Spanish for chapter hall), a meeting hall that has hosted numerous historical events, such as the proclamation of Admiral Ramón Power y Giralt as the first representative for Puerto Rico at the Cortes de Cádiz in Spain in 1812 and the signing of the abolition of slavery in Puerto Rico in 1873.

[2] The city hall also hosts the San Juan Bautista Gallery, which often showcases works of art made by local artists.