The municipality lies on the northern slopes of the long dormant volcano Mount Makiling and is known among tourists for its hot spring resorts.

Because of the town's proximity to Metro Manila, Los Baños's hot spring resorts (along with those in the preceding city of Calamba starting at Barangay Pansol) are frequent weekend or summer getaways for residents of the vast metropolis and tourists from primarily the National Capital Region (Metro Manila area) and other places in the Philippines, and abroad[citation needed].

[10] Los Baños started as a settlement, a barrio of Bay called Mainit, the Tagalog term for "hot", alluding to the thermal springs at the foot of Mount Makiling.

In 1595, a temporary building made of bamboo and cogon was built to serve as shelter for the patients who journeyed to Mainit to seek cures for their ailments.

The UPCA became a Japanese prisoner of war camp for nationals of the Allied countries, a target of Kempetai punitive measures, and the headquarters of a secret organization of guerrillas.

[14] The social unrest which arose when Ferdinand Marcos' debt-driven campaign spending led to the 1969 Philippine balance of payments crisis [15][16] spread beyond the capital and also triggered protests by students in UP Los Baños, most prominently in the form of a 13-day strike which saw barricades established at the UPLB Gate and Los Baños Highway Junction areas.

[17] When martial law was declared in September 1972, Marcos cracked down on any form of criticism or activism, leading to the arrest of many of Los Baños residents.

[18] Among those confirmed to have been martyred for their beliefs was Manuel Bautista, the student leader who had spearheaded the establishment of UPLB's Textbook Exchange and Rental Center (TERC).

[20] On August 7, 2000, Los Baños was declared a Special Science and Nature City of the Philippines by virtue of Presidential Proclamation No.

It leased office spaces until late 2010s from the DENR-Ecosystems Research and Development Bureau (ERDB), located at the College of Forestry, University of the Philippines Los Baños (UPLB) until it moved to its newly built own buildings at a parcel of land near the University Health Service (UHS/'Infirmary') towards the late 2010's/early 2020's, which coincided with a foundation anniversary celebrations of the organization.

[citation needed] On December 3, 2020, firing from outside the perimeter walls, its incumbent mayor Caesar P. Perez was assassinated inside the municipal office premises by an armed assailant,[23] with a former opposition councilor suspected to be the mastermind.

[24] Los Baños is nestled between two of Southern Luzon's most dominant geographical features – Mount Makiling to the south and south-west and Laguna de Bay to the north.

Others call it "alligator lake", a reminder that it served as the last bastion of Laguna de Bay's once-plentiful cayman population, which has since been wiped out and is now just another legendary part of Philippine history.