Las Piñas, officially called the City of Las Piñas (Filipino: Lungsod ng Las Piñas), is a city in the National Capital Region of the Philippines. According to the 2015 census, it has a population of 588,894. Las Pinas is bounded to the northeast by Parañaque; to the southeast by Muntinlupa; to the west and southwest by Bacoor; and to the northwest by Manila Bay. Half of its land area is residential and the remaining half is used for commercial, industrial and institutional purposes. The present physiography of Las Piñas consists of three zones: Manila Bay, coastal margin and the Guadalupe Plateau.
Las Pinas was established as a small fishing port and became a major sea salt-producing municipality, through the use of salt evaporation ponds, dating back to the Spanish Era, the city has grown into an important residential, commercial and industrial suburb of Metro Manila. The Sarao Motors factory, also located in Las Piñas, is the place where jeepneys are assembled piece by piece in painstaking individual production. The factory remains open to buyers and curious tourists all year round. Las Piñas also houses SM Southmall, which has an area of 205,120 square meters and is located along Alabang–Zapote Road. The newest shopping mall development in the city is Robinsons Place Las Piñas. The first high-rise building in the city is the 16-storey residential Almanza Metropolis. The story about the true origin of the city's name, "Las Piñas", varies. One version mentioned, that traders from the province of Cavite and Batangas shipped their first piñas (Spanish for pineapples) for sale to this town, before they were distributed to nearby markets. Another version related, that it was "Las Peñas" (the rocks), evident by the quarrying of stones and adobe, which were used to construct buildings and bridges. The old church bell, from St. Joseph Parish Church, founded by Diego Cera, has been preserved inside the church museum. An inscription on the bell states, "Siendo cura del pueblo de Laspeñas el M.R.P. Padre Diego Cera se fundió este equilón año de 1820," showing, that even during the time of Diego Cera, the town's first parish priest, that the town was called "Las Peñas", for sometime and eventually, was renamed "Las Piñas".
Las Piñas was one of the earliest fishing settlements on the shores of Manila Bay. It was proclaimed as a town of Manila province either in 1762 or 1797. Agustin de la Cavada, a Spanish historian, and Fr. Juan de Medina placed it at 1762. Las Piñas was formerly called "Las Pilas" due to its separation from Parañaque due to tribal conflicts. On the other hand, Manuel Buzeta recorded the date at 1797. Felix Timbang was the first gobernadorcillo in year 1762 while Mariano Ortiz was the first municipal president of the town of Las Piñas. Besides being famous for its Bamboo Organ, which was built by Fr. Diego Cera and completed in 1824, the town of Las Piñas was also a major war theater during the 1896 Philippine Revolution, as it was occupied by forces of Gen. Emilio Aguinaldo. Las Piñas was occupied by the Japanese during World War II and liberated by the combined American and Filipino forces. In 1901, the municipality of Las Piñas was separated from Manila and incorporated to the newly created province of Rizal pursuant to the Philippine Commission Act No. 137. Two years later, in accordance with Act No. 942, it was combined with the town of Parañaque, with the latter as the seat of a new municipal government. It was separated from Parañaque to become an independent municipality again on March 27, 1907 by virtue of Philippine Commission Act No. 1625. On November 7, 1975, through Presidential Decree No. 824, Las Piñas was excised from the province of Rizal to form Metro Manila, Las Piñas became one of the municipalities making up the region.
On February 12, 1997, President Fidel V. Ramos signed the bill which elevated Las Piñas from municipality into a city. A plebiscite held a month after approved the city status by its residents, and Las Piñas became the 10th city of Metro Manila on March 26, 1997. Las Piñas, like other cities of the Philippines, is a local government unit whose powers and functions are specified by the Local Government Code of the Philippines. In general, as a city, Las Piñas is headed by a mayor who heads the city's executive function and the vice mayor who heads the city's legislative function, which is composed of twelve councilors, six each from the city's two city council districts. For representation, the city is considered as one district, and therefore one representative, in the country's House of Representatives. Additionally, like other cities and municipalities, Las Piñas is subdivided into barangays. Las Piñas is divided into 20 barangays. These barangays are grouped into two legislative districts, each with its own set of representatives in the city council. District 1 comprises the northwestern half of the city while District 2, the remaining half.