I happened upon this structure as I made my way over to check out the new Los Vientos trailhead to the park on my hike, and knew I'd have to mark it with a cache. You're looking for a plus-sized pill bottle.
Hassler Health Farm, formerly known as San Francisco Health Farm between 1927 and 1931, was a tuberculosis sanatorium for patients of the San Francisco Bay Area, owned by the City of San Francisco. It was located in a remote part of San Mateo County, California, in what is today San Carlos, until 1964. After the discovery of antibiotics, tuberculosis became a reduced threat, leading the building to be converted into a hospital for the poor. It was closed in 1972 and sat empty until 1985, when the buildings were demolished.
Read more about the area's history at wikipedia.org/wiki/Hassler_Health_Farm
Please respect park hours of half an hour before sunrise until half an hour after sunset.