RVing in the summer is pure freedom … well, at least until the temperature spikes and your A/C starts playing catch-up. Whether you’re boondocking in the desert or baking in a full-hookup spot, sometimes you just need a break from the sun. And when you do, few things beat heading underground. And coast to coast, there are countless incredibly cool caves to explore.
Caves stay naturally cool — usually between 50 to 60 degrees Fahrenheit — even when it’s scorching outside. But these underground openings are more than just a safe haven from the heat. Each one feels like its own secret world, filled with unique formations, history, and a quiet sense of awe. If you’re mapping out summer road trip stops, these underground destinations deserve a place on your list.
So, here are five of the best caves to explore when the heat kicks in — plus one bonus spot that’s definitely worth the detour.
1. Carlsbad Caverns – Carlsbad, New Mexico
Let’s kick things off with a personal favorite: Carlsbad Caverns. It’s hard to describe just how jaw-dropping this place is until you’re walking down the Natural Entrance Trail and the cave starts swallowing you whole. The path winds deeper and deeper until suddenly, you’re standing in the Big Room — a chamber so massive it feels like it belongs in a fantasy movie. Honestly, the whole experience reminded me of something out of The Lord of the Rings.
The air down there holds steady around 56 degrees Fahrenheit, so it’s an instant relief from the sun. And if you time it right, you can catch the evening bat flights during summer — thousands of them swirling into the sky at dusk. It’s the kind of moment that sticks with you long after you’ve left.
Why it’s on this list: It’s iconic for a reason. Carlsbad is big, bold, beautiful, and surprisingly easy to access. Just bring a light jacket — and your sense of wonder.
2. Mammoth Cave – Mammoth Cave, Kentucky
If you’re going for sheer size among caves to explore, Mammoth Cave takes the crown. With over 400 miles of explored passageways, it’s officially the longest cave system in the world. But the real draw here is how customizable the experience is. Whether you’re into easy strolls or don’t mind crawling through tight spaces with a helmet and headlamp, there’s a tour for you.
If you get to the visitor center early (or have some time to kill before your tour), there’s a river trail that loops around nearby. It’s a relaxing hike with some beautiful views of the Green River and surrounding forest — a nice bonus if you’re stretching your legs after a drive.
Why it’s on this list: It’s massive, diverse, and surrounded by quiet natural beauty. From underground chambers to riverside trails, Mammoth gives you options.
3. Wind Cave – Hot Springs, South Dakota
Wind Cave might not be the biggest, but it’s definitely one of the most fascinating. It’s famous for its rare “boxwork” formations — thin, honeycomb-like structures you won’t see in many other caves. The cave itself is cool (about 53 degrees Fahrenheit) and feels like a quiet retreat beneath the prairie. But what really sells this stop is what’s waiting for you when you come back up.
Wind Cave is smack in the middle of South Dakota’s Black Hills, which means you’re just a short drive from some seriously epic destinations: Mount Rushmore, Crazy Horse Memorial, and Custer State Park, to name a few. You can go from watching bison graze to descending into ancient limestone tunnels — all in the same day.
Why it’s on this list: It’s the perfect mix of natural wonder above and below ground. If you like variety in your travel days, Wind Cave delivers.
4. Great Basin National Park – Baker, Nevada
This one flies under the radar — and that’s part of what makes it so great. Tucked away near the Nevada-Utah border, Great Basin National Park feels like one of the last truly quiet corners of the National Park system. It gets a fraction of the visitors you’ll find at places like Yosemite or Zion, which means you can really take your time and soak it in.
Lehman Caves, located right inside the park, offers marble passages filled with rare formations, and the ranger-led tours here are excellent — detailed but not too scripted. The cave stays a brisk 50 degrees Fahrenheit, and the whole place has a peaceful, remote vibe that’s hard to find anywhere else.
Why it’s on this list: Low crowds, incredible cave features, and a refreshing sense of solitude. If you like your adventures a little off the beaten path, this is the one.
5. Oregon Caves National Monument – Cave Junction, Oregon
Nestled in the forested Siskiyou Mountains, Oregon Caves is a marble cave system that feels entirely different from the others on this list. It’s more intimate — narrow passageways, glittering stonework, and a bit of a mystical vibe thanks to the surrounding old-growth forest. It’s also the coldest cave here, holding steady around 44 degrees Fahrenheit. You’ll definitely want that jacket for this one.
Tours here involve stairs and tight corners (so it’s not for everyone), but it’s incredibly well maintained and feels like a true escape from the modern world.
Why it’s on this list: Scenic, quiet, and tucked into a beautiful part of Oregon. If you want to pair a peaceful forest setting with a deep, chilly descent, this one’s a gem.
Bonus Cave: Lava Beds National Monument – Tulelake, California
Lava Beds is a bit of a choose-your-own-adventure destination. Instead of structured tours, you’ve got lava tubes—lots of them—and most are open for self-guided exploration. Some are wide and easy to walk through; others are tight, pitch-black, and not for the claustrophobic.
Bring your own headlamp and helmet (or rent at the visitor center), and be ready to get a little dirty. It’s not your typical cave experience, but if you enjoy rugged, hands-on exploration, you’ll love it.
Why it’s a bonus: It’s unconventional, raw, and a total blast — if you like a little DIY adventure with your underground time.
Pro Tips for Caving in the Summer
- Book ahead. Popular caves to explore like Carlsbad and Mammoth fill up fast in peak season.
- Bring a jacket or hoodie. Even on the hottest days, caves are chilly.
- Wear sturdy, closed-toe shoes. Many tours require them — and you’ll be glad you did.
- Don’t forget the basics. Water, snacks (outside the cave, of course), and a flashlight if allowed.
- Mind the rules. Some caves have protocols to prevent the spread of white-nose syndrome among bat populations. Be respectful.
Make It a Scenic Drive
One of the best things about adding caves to your itinerary is how well they pair with a good road trip. These caves are scattered across some of the most scenic drives in the country — from desert stretches in New Mexico to forested mountain routes in Oregon. The drive to each cave is often just as memorable as the cave itself.
If you’re building out your route, peppering in some caves to explore give you some excellent pit stops between national parks, state forests, and other summer destinations.
Caves with Cool Air and Wild Places to Explore
Sometimes the best memories are made when you slow down, veer off the main road, and try something a little different. That’s what makes caves so special. They’re quiet. They’re cool. And they’re filled with beauty that most people drive right past.
So this summer, when the heat gets to be a little too much and your next destination feels just a little too far, pull over, head underground, and cool off in one of these incredible places. You might just find your new favorite detour.