It is located at the west central part of the city, on the northern bank of the Pasig River[2] bounded by the districts of Binondo to the east by Estero de Binondo, and Tondo to the north and west, and by the Pasig River to the south.

[1] The town of San Nicolas was originally named Baybay, meaning "shore" in Tagalog.

[3][4] According to Piet Van der Loon (1966), a Sangley Chinese community had already settled in Baybay near Tondo on the banks of the Pasig river, before the Spanish conquest of Manila in the Battle of Manila (1570), and way before the market at Parián (modern-day Arroceros Urban Forest Park) attracted large numbers of traders and craftsmen, especially immigrants and merchants from Southern Fujian,[5] so before Parián and Binondo became the local Chinatown of the area, Sangley Chinese settlers and merchants were already living in Baybay in between Tondo and old Manila (modern-day Intramuros) on the south bank of the Pasig river.

During Spanish rule, Baybay was renamed to San Nicolas, after the patron saint of sailors, boatmen, and mariners.

[8] Daniel Burnham, an American architect and urban planner, was commissioned to build a Plan of Manila.