No caves here in NY suburbia. I'll let the Californians speak for themselves, but except for lava caves in the north, and sea caves around, for example, the northern Channel islands, I think there is a shortage of big caves....the geology is really different...not a lot of limestone,,,which is more common in the areas you hang out (or hang under..).
(I hear eartones but doubt that those that I hear have anything to do with earthquakes...I'm speaking for what I hear, I'll give what others hear a rest for now.)
Chris