Green Grotto Caves

[yetta]

Sounds really cool. I googled it and here is their website. Apparently, near Discovery Bay. I'll add another link or two also. May have to check this out myself.

http://www.greengrottocavesja.com/v1/index.htm

http://en.wikipedia.org/wiki/Green_Grotto_Caves

http://www.yardietours.com/html/grotto.htm