Barangay Lag-asan, one of the biggest barangays in the City was formerly a cluster of small haciendas divided by a river. In the south are the haciendas of Javellana, Genete and that of the Montilla families, popularly known as Ubay, Lag-asan. Found in the north, are haciendas of the Aranetas and that of the late Antonio Varela. This river dividing the haciendas played a great role during these days. At the bank of this river was a small pier where only raft and bancas used to carry passengers crossing the river. As the only linkage to the other side from far south of Negros dropped at this little pier in going to Bacolod. Well to do families with cars also took this rafte to carry their car to the other side, thus this small place became a busy trading center. There were times when disagreements arose and it is here where they usually run one after the other. Sometimes, robbers and hoodlums being run after by the residents were caught in this place, because they had no other means of crossing but by the rafts. It was then that during these days, residents of this place used to call it Lag-asan, from a local dialect meaning, a place where people usually run after another.
Barangay Lag-asan is located in a very convenient place accessible to all kinds of land transportation. It is about 1 V-i kms from the city proper and being traversed by developed road networks. It has a total land area of 436.340 hectares.
The barangay is proud of its old and historical Bago Bridge, once defended by an American soldier Theodore Vinther from the hands of the Japanese soldier in WWII, which event hastened the liberation of Negros.