Mysterious rock staircase discovered in San Diego sea cave

Talk about a blast from the past — and a deep dive into California’s underworld.

Daring explorers have ventured into a treacherous, seawater-filled cave beneath San Diego’s iconic Sunset Cliffs, capturing eerie footage of what appears to be a long-forgotten staircase carved into the rock. The footage has reignited an old mystery involving Prohibition-era bootleggers and a secret passage to a mansion.

The jaw-dropping footage, shared by Turkish news account Bulvar Medya on X, shows explorers navigating the pitch-black cave as waves churn around them, illuminating the rocky interior with flashlights. In the video, two barefoot men squeeze through a claustrophobic, partially submerged opening barely wide enough for their bodies before emerging into a labyrinth of towering, rock-walled corridors.

They make their way through the passages, pointing out what they describe as “carvings for candles” along the walls of the narrow chambers hidden deep inside the cliffs. The explorers compared the space to the catacombs.

The eerie scenes offer a rare glimpse inside the coastal caverns that have fueled decades of rumors about Prohibition-era smugglers, hidden escape routes and a secret tunnel leading to a mansion perched above the Pacific Ocean.

But the most tantalizing question isn’t what’s beneath the waves, but where the mysterious passageways may have once led. According to local lore, the cave was once a clandestine hideout for rumrunners who used San Diego’s coastline to sneak illegal booze into the country during Prohibition.

“The cave at Sunset Cliffs is said to have been used by bootleggers in the past and connected to a historic mansion by a secret tunnel,” the outlet wrote on X.

The cave, commonly known as Rum Runner’s Cave, is located along Sunset Cliffs — a spectacular stretch of coastline famous for its rock formations and hidden caverns.

Although the footage has brought fresh attention to the mystery, the staircase itself is not a new discovery. The cave and its unusual man-made features have been the subject of local fascination for decades, with accounts documenting the carved steps, sealed-off passages, and possible connections to other properties.

Known locally as the Pink House, the historic Osprey Mansion has long been linked to rumors of underground passages and covert activity. In a June 2026 article published by local outlet OB Rag, writer Steven Franklin, who recalled spending time inside the mansion, described an extraordinary hidden feature.

“There is the false wall built into a mahogany closet under the stairs, for example,” he wrote. “When you push one side, just like out of Count Dracula or some international spy and intrigue film, the entire wall rotated with a creaking sound, exposing a dark stairway leading down to the entrance of a secret tunnel below.”

The account added another twist to the mystery surrounding the passageways.

But exploring the caves is no casual sightseeing trip. The narrow openings can fill rapidly with seawater, while surf, changing tides and slippery, unstable rock formations pose potentially deadly hazards.

San Diego officials have warned against entering the area’s sea caves because of the dangerous conditions.

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