Have you visited Joshua Tree without exploring the mysterious Iron Door Cave? If so, you’re like most others. This hidden spot holds secrets into the dark history of the land before it became the National Park that we all know and love today. 

Deep within the rocks inside the boundaries of Joshua Tree National Park, lies a man-made cave built into a boulder with a bizarre iron door leading inside.

The Iron Door Cave isn’t recognized as an attraction or on any maps made by the NPS. Only some in-the-know visitors and a few rock climbers who have stumbled upon the cave know about it. 

On our recent trip to Joshua Tree, after some searching, we did find the infamous Iron Door Cave. So, I wanted to make this guide for all the other adventurous travelers out there who are looking for something a little more off the beaten path on their trip to the park.

Who Made the Iron Door Cave?

In the early 1900s, a man named Bill Keys decided to establish a ranch and raise his family in the desert of what is now Joshua Tree National Park.

If you’ve already visited the park, you may be familiar with or have seen signs for “Keys Ranch”. This was the area where he chose to homestead.

Today, you can book tours of his property to get an inside look of what it took to live in the brutal Mojave Desert. He pursued mining and ranching to survive and make a living to support his family.

Bill Keys occupied nearly 100 acres of the park which now is present day Keys Ranch, Barker Dam, and the Hidden Valley Campground.

In the middle of a boulder field on his property, he built the Iron Door Cave inside a massive boulder.

This cave is very well hidden within the rocks, you wouldn’t even know it’s there unless you’re looking for it or exploring every crack and crevice in the park. 

Why Was the Iron Door Cave Built?

What makes the Iron Door Cave so interesting and mysterious, is that no one knows EXACTLY what it was built for. There are speculations and theories but we do not know for certain. 

With research I have found that the two most probable reason Keys made the cave was to either:

• Have a safe place to store his dynamite
  • Dynamite was frequently used for mining operations. They might’ve also used it to blow up the native ground and rock so his family could plant a garden with better soil
• Use as a prison to keep his mentally ill son
  • Keys had a “deranged” son and rumor has it the son was caught cannibalizing one of Key’s ranch workers
  • There is an opening on the inside of the cave which could have been used as an “air hole” so this theory could still be true

The fact that the NPS doesn’t recognize the cave as part of the park makes it more suspicious to me. It leads me to believe it was used for more cynical purposes other than just storing dynamite. 

Where is the Iron Door Cave?

If you’re staying at the Hidden Valley Campground, you’re in luck. Because the cave is just a short walk away.

As you can see it’s located in the middle of the huge valley of boulders (called Wondlerland of Rocks) behind the campground. Kind of fitting that the campground is named “Hidden Valley” with the hidden secret that lies just within reach.

Parking

There is a very convenient small parking area right across from the campground. It’s more like a pull off on the right side of the Barker Dam Road. You can’t miss it.

The pull off is only big enough to fit about 6 cars. It seems to mostly be used by rock climbers who frequently boulder in the Hidden Valley area. And of course the few of us looking for the Iron Door Cave.

I do want to make note that there is nowhere to park in the actual campground. The parking spaces, and campsites are reserved for the visitors who are camping in those spots. If you have a reservation in Hidden Valley then you’re in luck, because you won’t have to walk as far! 

How to Get There

While we were in the park, we just put in directions to the Hidden Valley Campground.

Service in the park can be spotty so try to get all your directions in your phone ahead of time wherever you can when you have service.

The pull off where you can park is around this area:

Hiking to the Iron Door Cave

Once we parked, we began walking up to the campground. We really had no idea where to even begin, but with researching ahead of time, I was able to locate the approximate direction of where the cave was. 

There is a pathway that goes around the campground on the right side. This is the trail we began walking on for about 5-10 minutes until we took a left into the Wonderland of Rocks.

You will have to walk on top of and around the rocks heading deeper into the boulders. You will want to be hiking north away from the campground. 

With several minutes of wandering you will eventually come upon a very large and round boulder. I know, most of them are, but this one is VERY round.

And just on the other side of the rock you’ll find a triangular hole in the rock at the bottom which is the entrance to the cave. 

It’s pretty hidden, my partner walked right past it!

You’ll likely see rock climbers scattered all around this area. In fact, there were a group of people bouldering on a rock just a few feet from the Iron Door Cave!

In total, we probably hiked about 1.5 miles to get to the cave. That’s including the walk from the parking area, and wandering around the Wonderland of Rocks.

Approximate Coordinates of the Cave

I am putting the coordinates here of the approximate location of the cave.

When we were there I placed this pin on my map. So this may not be exactly where the cave is, but this pin will take you to the general area. Plus, half the fun is exploring and trying to find it. 😉

However, I know that most visitors don’t have all the time in the world to walk aimlessly around the desert looking for the Iron Door Cave. I know we didn’t. So hopefully these coordinates will help you out.

Exploring this area just makes you wonder, what other dark secrets are hidden within the park that we don’t know about yet? Spanning 800,000 acres, Joshua Tree is bound to carry more hidden spots that may not even be discovered in our lifetime.

I hope this guide helped you find the Iron Door Cave in the park and thank you so much for reading!