"I grew up in Santa Ana in the 1950's - 60's. I remember so many of these great memories posted. It really brings me back! I'm wondering if anyone remembers the Caves at Irvine Park? My parents took my sister and I most weekends and we would crawl around and explore these fantastic caves. Also at the park were holes in the ground where tarantula's lived. Sometimes people would pour oil (believe it or not) down the holes in order for them to come up. Then would trap them in cages, and I guess sell them."
I've never heard of them.
There is the "Robber's Cave" at Aliso Woods Canyon, but that's much further south.
Can anyone else add to this?