Well, it's actually a regional park, the oldest municipal park in the state of California, according to Wikipedia.
But for much of its early life, San Jose's Alum Rock Park was also a health spa. Between 1890 and 1932, the 27 mineral springs that run into Penitencia Creek were located and given their own small grottos. In addition, a railway line, swimming pool, tea garden, dance pavilion and a variety of privately owned bathhouses were built to accommodate visitors.
Today, most of those facilities have been dismantled and the park is oriented much more towards the direct and unmediated appreciation of nature. But the stone-built grottos along the creek remain, still dribbling out waters loaded with iron, calcium, sulphur and more. None feature alum, as it happens.
I knew none of this history (there's more here) until visiting the park yesterday. It's a lovely place - clearly popular with locals, and full of wildlife. The disused grottos are fascinating -- modern artifacts with the aura of something ancient that you might stumble upon in Tuscany or Greece.
