It is hard to find parking in La Jolla.

It's a neighborhood perched on a cliff in northern San Diego.

The streets are narrow and the sidewalks are sandy.

Every 10 feet, there's a trendy brunch place or a boutique or a gelato shop. But down the hill on the bluff, there's a line of

15 people parked on the sidewalk in front of a wood-shingled store. Inside this normal looking store,

there's a tunnel, a long staircase that leads underground through the cliff and spits you out inside a secret cave.

This passageway is the only way to get there from land.

Every few minutes, the people waiting to enter the tunnel get to watch someone emerge from it.

Small groups spill onto the sidewalk, out of breath, maybe a little sweaty.

I didn't think it would be that steep.

So many stairs.

Oh, my cops are.

What would you rate it on a scale of one to ten?

Um, 50,000, no.

50,000 out of ten?

I think I'd rate it three trillion.

Mm-hmm.

I'm Sarah Wyman, and this is Atlas Obscura,

a celebration of the world's strange, incredible, and wondrous places.

Today, we're going down that long set of wooden stairs to see a spectacular, hidden view of the Pacific Ocean.

And a sea cave with a mysterious and colorful past.

We descend into the tunnel and the Sunny Jim Cave, I was sort of picturing a speakeasy, a closed door in the back of the shop where you'd have to knock three times or something before the door would open quickly from the inside and you'd sneak down the dark tunnel.

...