There was a legend that during the early days of the Spanish occupation, a "Guardia Civil", while making his tour of duty in what is now the town of Calamba, met a young woman who had just been to a nearby river carrying a jar of water. The guard inquired for the name of the place. In her confusion, the woman answered "kalan-banga" after which she scurried away. Since then, this town has been called Calamba. To immortalized the town's legend, a big concrete jar was constructed in the town plaza with the names of the barrios inscribed in it.

Calamba hugs the coast of the southern tip of Laguna de Bay, in the Southern volcanic region of Luzon lying at the foot of Mount Makiling. It is bounded on the east by Laguna de Bay, a rich source of fresh water sources - a blessing to many fisher folks; on the north by Cabuyao, also an upcoming industrial municipality, on the south by Los Baños a place noted for its natural springs and the internationally known University of the Philippines; on the west by Santo Tomas, Batangas, a town noted for its coffee, sugarcane and coconut plantation. Calamba is classified as Class A-1 municipality. It is 54 kilometers away from Manila and only an hour ride passing through the South Expressway.