Mysterious underwater 'UFO base' believed to be alien hub spotted off Southern California coast

A mysterious underwater formation known as Sycamore Knoll has once again captured public attention, following fresh speculation over its possible extraterrestrial origins. Located approximately 6.6 miles off the coast of Malibu, Southern California, the formation has long intrigued scientists—and now conspiracy theorists too. According to a report by the Daily Mail, the structure appears as a raised bump on the ocean floor with a flat, table-like top. It lies about 2,000 feet below the surface at coordinates 34° 1'23.31″N 118° 59'45.64″W.

(Also read: Declassified CIA document says ‘aliens’ turned 23 soldiers to stone in otherworldly encounter)

A digital disappearance

According to outlet, Google Earth imagery from 2014 showed detailed views of Sycamore Knoll, sparking a wave of public interest. However, the formation appears to have been removed or blurred on the platform as of 2025, further fuelling the mystery. Some users argue that the blur is simply due to incomplete data.

One Redditor remarked on a post about Sycamore Knoll, “Some refer to it as an anomaly while others believe it is an alien base. It's believed to be between two-and-a-half and three miles wide.”

UFO sighting rumours

Sycamore Knoll first gained mainstream attention in 2014 when it featured on the Fade to Black podcast with host Jimmy Church, who described it as possibly “the biggest centre of UFO activity since Roswell," reported the outlet.

Adding fuel to the theories, Congressman Tim Burchett recently claimed an unnamed admiral told him of an underwater UFO “as large as a football field, moving at hundreds of miles per hour.”

As per the outlet, one California resident reported seeing a glowing structure above the site: “It looked like a massive, cathedral-shaped structure — multiple pointed edges all glowing brilliantly white, heading straight into the ocean. There was no splash, no sound... just a flash, and it was gone.”

Bombshell claim

The renewed focus on Sycamore Knoll coincides with a new release by Jeremy Corbell, a filmmaker and investigative journalist known for covering military-documented UFOs, as per the outlet. He recently shared new video footage taken aboard the USS Jackson in 2023, which shows what he described as a “self-luminous, wingless, tailless” craft emerging from the Pacific Ocean.

(Also read: Mysterious triangle tower spotted on Google Earth at Area 51 sparks wild alien theories)

As per the outlet, Corbell said the object resembles those seen in the famous 2004 Nimitz and 2019 Navy UAP encounters, all within Warning Area 291, the same region where Sycamore Knoll sits. “This is not a one-off; these intelligently controlled craft have been appearing for decades,” Corbell said.

A Navy CIC operator reportedly tracked the 2023 object using thermal targeting systems, observing four UAPs that executed a coordinated manoeuvre before vanishing—no visible propulsion, just raw speed and synchronicity.