In California, you can tour these military bases for free

California is home to some two dozen military bases, including storied installations such as Edwards Air Force Base, where Chuck Yeager broke the sound barrier, and little-known facilities such as the Marines Corps Mountain Warfare Training Center in the Eastern Sierra.

But what goes on behind those heavily guarded gates? Without proper identification, you can’t pop in for a look-see, so many of us have only a vague idea.

The good news is that several California bases offer public tours that give visitors a behind-the-scenes look at how the armed forces are working to meet the nation’s complex security challenges.

Some tours fill up far in advance — Edwards is booked through 2020 — so be sure to contact the installation you’d like to visit as soon as possible. You may need to fill out a registration form and undergo a security check, but you don’t need to pull out your credit card: Base tours are free.

National Training Center and Ft. Irwin

If you’re looking for a kick-ass tour with things that go boom and rat-a-tat-tat, you can’t do better than the six-hour experience at Ft. Irwin, the Army’s massive pre-deployment center northwest of Barstow.

Your tour bus will rumble through miles of creosote-studded desert before depositing you at a 1,200-square-mile training area called “the box” (short for sandbox). It’s brutal terrain and — except for a faux village with mock mud-brick houses — wide open, making it ideal for brigade-on-brigade war games that can involve as many as 5,000 fighters on each side.

You won’t be able to watch a real training exercise, but you’ll get a taste of the action during a mock battle that features soldiers exchanging rifle fire, a fake IED explosion, a helicopter buzzing low and lots of smoke.

If you’re game, you can crawl inside a personnel carrier or get down on your belly and fire a tripod-mounted machine gun. (The gun shoots blanks but it’s still loud as heck, so take advantage of the free earplugs.)

Your day at Ft. Irwin will involve lots of make-believe, but there’s nothing fake about lunch: a genuine, military-issue MRE (meal, ready to eat).

Info: National Training Center, Ft Irwin, bit.ly/fortirwintour. Eight tours per year. No children younger than 12. Reservations accepted 30 days before the tour date; upcoming tours are Feb. 7, March 6 and April 3.

Vandenberg Air Force Base

The (mostly) windshield tour of California’s preeminent launch port and test range should be on every space nerd’s bucket list.
Vandenberg, in coastal Santa Barbara County near Lompoc, offers a 90-minute bus excursion that will get you about as close to an active rocket-and-missile launch pad as you will get anywhere.

As a space port, Vandenberg is ideally positioned on California’s “elbow,” which allows rockets to head south without flying over a large land mass.

All sorts of government, military and commercial payloads launch from this 99,000-acre installation, some of them crucial to national security. Vandenberg was the launch site for the ground-based interceptor that recently shot down a simulated, incoming warhead from the central Pacific.

Test firings of the Minuteman intercontinental ballistic missile, the nation’s nuclear deterrent, go up from Vandenberg. NASA’s latest Mars explorer blasted off from Vandenberg. The base’s launch pads are also used by United Launch Alliance, whose Delta IV heavy rocket can thrust a payload the size of a 44-seat passenger bus.

A lot of what goes on here is hush-hush (think spy satellites), so photography is tightly controlled. Our group was permitted photos only at ULA’s Space Launch Complex 6, from which the Delta IV hurtles into the wild blue yonder.

Someone on our bus joked that the sale of Vandenberg’s 42 miles of protected coastline could retire the national debt in 24 hours. That sounds like a stretch, but the Vandenberg tour is a rare opportunity to soak in the heart-stopping beauty of a stretch of Central Coast that is off limits to pretty much everyone except those with base access.

You can also schedule a separate visit to the base’s Space and Missile Heritage Center, which displays launch complex models, rocket engines, re-entry vehicles and more.

Info: Vandenberg Air Force Base, 747 Nebraska Ave., (805) 606-3595, vandenberg.af.mil/Public-Tours. Tours offered at 1 p.m. on the third Tuesday of every month; upcoming tour dates are April 21, May 19, June 16 and July 21. Space and Missile Heritage Center offers tours four times a year; the next available date is Jan. 26, 2021, vandenberg.af.mil/Public-Tours

Marine Corps Air Ground Combat Center, Twentynine Palms

Mock villages have sprung up at numerous bases but none is quite like the Marines’ urban warfare training center at Twentynine Palms, 150 miles east of Los Angeles.

On a six- to eight-hour visit to the country’s largest Marine base, you’ll ride a bus deep into the desert until a fake city comes into view, complete with hundreds of buildings fitted out to look like homes, shops and hotels.

This is where Marines, sailors and U.S. coalition partners prepare to fight in an urban environment. You won’t be able to watch a real exercise but you’ll still have an action-packed experience.

You can fire a .50-caliber machine gun (modified with compressed air) at virtual-reality enemies that are projected on a wraparound screen in an octagonal-shaped room.

Or you can put on a helmet and flak jacket and strap yourself into the back of a mine-resistant ambush-protected (MRAP) troop carrier that is attached to a special frame and rotates 360 degrees on its axis.

Our group screamed when we turned upside down, but this equipment is no carnival ride. In the field, MRAP rollovers are not uncommon and can be fatal, so the exercise helps service members learn how to find a hatch and get out of the vehicle — fast.

Info: Marine Corps Air Ground Combat Center, (760) 830-3735, bit.ly/29palmstour. No tours in June, July and August. Must be 16. Visitors must be able to walk through deep sand and on rugged terrain. Water provided.

Marine Corps Base Camp Pendleton

The Marine Corps Mechanized Museum at Camp Pendleton, 38 miles north of downtown San Diego, will bring back memories for anybody who has ever driven, ridden, crashed or cussed at a military vehicle.

The museum is in an old railroad terminal and offers docent-led tours of about 150 items, focused on engine-powered vehicles. Among the earliest is a Ford Model T ambulance from World War I (it still runs); the newer pieces include a light tactical vehicle from the Iraq war. The “movie star” here is an amphibious landing craft that director Clint Eastwood borrowed for the film “Flags of Our Fathers.”

Your museum visit can be combined with a docent-led tour of one of Camp Pendleton’s historical assets,
a circa 1840 ranch house that was home to Pío Pico, the last governor of Mexican California, and later housed families of Marine generals.

Info: Marine Corps Base Camp Pendleton, (760) 725-5758, pendleton.marines.mil. Mechanized Museum tours Mondays-Fridays and weekends by appointment. Ranch house tours first Tuesday and Thursday and second Thursday of every month; weekends by appointment.