“People who say they don’t believe in ghosts—it’s true until you see one. Then when you have the experience, you’re definitely a believer." That's according to Richard Senate, an experienced ghost hunter and author of 23 books, including Ghost Stalkers Guide to Haunted California and Ghosts of Santa Barbara.

Senate joined Soterios Johnson on a recent episode of the California Now Podcast to share his favorite haunted places in the Golden State. Listen to the episode to hear Senate’s personal tales of mysterious monks, icy cold breezes, and doors that mysteriously open and close. Experience a ghoulish Golden State encounter yourself by visiting one of these haunted haunts—just in time for Halloween.

The Whaley House Museum, San Diego

This private home-turned-California Historical Landmark is one of the longest-standing structures in San Diego—and according to Senate, one of the city’s most haunted. Located in the Old Town district, visitors have reported seeing the ghost of James “Yankee Jim” Robinson, a thief who was hung on the property for stealing a boat, as well as Thomas and Anna Whaley. Senate recommends signing up for a docent-lead nighttime tour and bringing a digital camera. After the tour, review your photos for “bits of mist or strange bolts of energy, or bars of energy, or even full-fledged apparitions,” he says.

The Queen Mary, Long Beach

The Queen Mary, a retired British ocean liner docked in Long Beach, has an eerie history—including reports of nearly 50 on-board deaths following its maiden voyage in 1936. Today the vessel welcomes guests for a number of spooky experiences including a Dining with the Spirits dinner and the Paranormal Ship Walk. For your best shot at a sighting, Senate says, stay the night in one of the cabins. Set your alarm for 2 a.m.—“the best time for ghost hunting”—and walk the decks. “It's almost as if seeing a ghost is natural and normal,” he says.

Alcatraz Federal Penitentiary, San Francisco

Surrounded by the icy waters of San Francisco Bay, this former high-security prison once held the country’s most notorious criminals, including Machine Gun Kelly and Al Capone. Even for a paranormal expert like Senate, Alcatraz has the power to petrify. Senate explains that for a radio show stunt, he volunteered to be locked in a punishment cell, an experience he calls “the most terrifying 15 minutes I ever spent.” See the former cell blocks for yourself on the Alcatraz Night Tour, complete with roundtrip ferry ride to San Francisco.

Winchester Mystery House, San Jose

Following the death of her firearm magnate husband, Sara Winchester moved from Connecticut to San Jose and immediately started construction on a mansion that would become the Winchester Mystery House. Full of curiosities, including doors that open onto walls and staircases that lead nowhere, the house was supposedly designed to fool the ghosts of men killed by Winchester rifles. Visit what Senate calls a “freaky joint” by booking a daytime tour any time of year, or opting for the after-dark Unhinged experience, offered around Halloween.

California Missions, Central Coast

Senate says that his very first ghostly encounter occurred in Mission San Antonio de Padua in Monterey County where the apparition of a single monk kicked off a lifelong passion and career. Today, he cites the Santa Barbara area as his go-to region for haunted missions: Mission La Purisima Concepción in Lompoc is reportedly haunted by ghosts of the Chumash tribe, while the Old Mission Santa Barbara is home to what Senate calls “a phantom monk… there to assist people who have problems, not frighten anyone.”