With an area of 468.8 hectares (1,158 acres), it is the smallest municipality in Camarines Sur, but it is the densest, having 4,755 persons per square kilometer, which is almost twice the density of the Naga City. The town is home to the oldest known pre-colonial site in the Bicol region, dating 500 AD to 600 AD, making it an undeclared important archaeological zone.
Camaligan is politically subdivided into 13 barangays.
The town proper is a known archeological site. From 2016-2017, hundreds of artifacts including shells, jar fragments, tools, other deposits, pig bones, deer bones, stingray cartilage, shark cartilage, and at least 15 pre-colonial human remains were found in the area, marking a revolutionary phase in Bicolano archaeology. The shells and tools found in the town dated back 1,500 years ago or approximately 500 AD to 600 AD. The site contained no trace of Chinese, Southeast Asian, or South Asia trade links, making Camaligan a pure pre-colonial Bicolano site.
The origin of the town and its name can be traced back to the early settlers of the place. Known as the “Canoadores” (Certadores) to the early Spanish colonizers who came to the place in the early Seventeenth Century (17th), the settlers cut timbers from nearby mountains located upriver or around San Miguel bay area and made this as their form of living. Out of these timbers they hewed out canoes or “bancas” which they stored under small sheds or huts. Later, when these sheds became abundant in the area, as they were made the permanent dwelling places by these canoe makers, the place was called “CAMALIGAN” from the word “KAMALIG” or shed, a place where so many “Kamalig” are found. The sheds served to shelter the canoe makers and protect their boats from the natural elements. Hence, the name and origin of the town is historically tied to the river and its early inhabitants.
The settlers of the religious visita of Nueva Caceres, which was then under its ecclesiastical jurisdiction, arrived in the town by the 17th century. The pre-colonial cemetery and community center of the people was transformed by the Spanish into the town's current church compound to diminish native belief systems and instill Catholicism. On 5 June 1775, a petition to the Spanish religious authorities was sent by the natives and signed by the supposedly officials of the place, to request for a resident curate. The officials’ names were: Andre Casa, Diego, Lobao, Simeon de la Cruz, Manuel del Espiritu Santo, Fernando Valenzuela, Agustin del Espiritu Santo, Marcos David, Domingo Flores, Pedro Negre, Bartolome Rodriguez and Valentine de los Santos.