The mineral springs located in this area have played an important role in the history and development of the park. Between 1891 and 1902, the Parks Commission began developing the park, highlighting the springs. During this period, over 20 different springs were identified, including sulfur, magnesia, iron and naturally carbonated soda springs. To protect and identify the different springs, tunnels were dug into the hillside and craftsmen were brought in to build the grottos (sic) and fonts that are found in this area. The masons created the stone grottos (sic) using native rock collected from the canyon. The intricate patterns and styles you see demonstrate the formality of the period.
The popularity of the springs and the surrounding park led to the construction of bath houses. The spring waters were piped to holding tanks, heated and used in the tile tubs of the bath houses. Many visitors to the park mistake the large basin type grottos (sic) for the baths, however, they are not tubs.
With development, the park gained popularity as a heath resort. Many people felt that the mineral water had certain medicinal values. From 1892 to 1902, eleven medical doctors, from the area certified that the waters were beneficial and recommended them for "kidney and stomach troubles, rheumatism and malarial afflictions."
Alum Rock Park Interpretive Series
San Jose Parks, Recreation and Neighborhood Services.