Haystack Rock's second cave, Cannon Beach

I've always been intrigued by this small cave on the extreme northwest side of the rock (not to be confused with the large cave on the south to west side). This is as close as I've been able to get to it, and can't really tell how far in it goes. Does anyone out there know? I'm sure there must have been times when the sand has built up to it, but I've yet to see that happen.

Done