Rumor goes that the tunnel used to lead to a house, but has since been closed off and the entrance to the house covered. Having been inside, I can see where the tunnel most likely took you to and it is not to a house. Check out these photos of what Sunset Cliffs used to look like:
There is a lot of rubble in this area, my guess is it the rubble of the ruins that used to be there. My point is things looked much differently than they do now. I have heard that there used to be homes directly along the cove. There most likely used to be a home that lead to the tunnel that no longer exists. Now all that remains is a closed up hole by the city leading to this amazing spot and broken rubble below.
Here are some stories I was able to get off the internet:
"Rum Runners from Mexico would navigate their dinghies up the little tunnel to a small underground elevator. This is a story I heard from my Grandparents and Uncles (who relocated to Ocean Beach after the war.) The tunnels are said to be all blocked off these days. I myself as a child would go hunting for these Prohibition Era caves."
"When I was in the navy in the late 1980s, my home port was in the San Francisco bay area, every so often we would fly to San Diego for training at a naval facility just north of Point Loma. Some nights we would go to the cave to light a fire, drink, and relax, this was 1988. I remember a skull carved in the wall that had candles in its eyes. I carved Van Halen logo, and my nickname, the Sappster. I wonder if those are still there."
"I was just in there last night with a couple friends, needless to say it's a sketchy experience. I fell 15 feet down a hole into a pool of stagnent water. pitch black. couldn't see anything. I had to swim under water to get out to the ocean, and find my way to shore so I could climb up to the main road and meet up with my friends again. sketchiest moment of my life." My advice: DON'T GO AT NIGHT!
"So i was showing those cave pics to a friend of mine(older guys)...great shots by the way joe and thanks for posting them...great memories..."i wonder if anybody has seen them that well lit up before in about 80 years or so"... and my aunty(hanai) says..."oh yeah...thats my grandfathers cave...WHAT?!?!...yeah the tunnel comes out under my old house and my grandfather used to smuggle booze through there...it got walled up many years ago before we sold the house...i doubt the new owners even know its there or where it was..."
Personal Experience: If you find it, come prepared with proper safety gear, good traction shoes, flashlight and candles to light the hallways! There was a draft the day we went so our candles kept blowing out. There are dangerous areas where you could fall into the water or back down to the bottom of the cave. Be very careful.
Other than that, it's like San Diego's own little Goonie's cave! There are multiple hallways that have been carved out with candle holders for the smugglers to see their way through. It sure is a trip to know this little secret is right below an area that thousands of people walk over monthly!
One of 3 entrances to this cave:
It's hard to tell from this photo, but that is a steep drop if you accidentally fall. This was the scariest part for me: