The PNR South Main Line (Filipino: Pangunahing Linyang Patimog ng PNR, also known as Southrail and formerly the Main Line South) is one of the two trunk lines that form the Philippine National Railways' network in the island of Luzon, Philippines. It was opened in stages between 1916 and 1938 by the Manila Railroad. Services peaked in the 1940s until the late 1960s, when the system started to decline. Since 1988, it was the only functioning inter-city rail after its counterpart to the north, the North Main Line, was closed. The intercity section of the line in Laguna, Quezon and the Bicol Region was then closed and reopened repeatedly between 2004 and 2014 due to a combination of declining ridership and was closed since then. Currently, only two short sections of the line survive; the PNR