Missouri is home to a wide variety of terrain, from grassy plains to thick forests, wide waterways to rocky cliffs. Its natural beauty makes it a playground for outdoor adventurers and families looking for unique adventures this summer. One popular option is to explore Missouri’s caves.

According to a recent press release by the Missouri Division of Tourism, the state is home to more than 6,400 recorded caves, more than any other state in the nation. Many are deep, expansive “show caves” that give visitors a glimpse of what lurks underground. Kirk Hansen, public relations director at Fantastic Caverns in Springfield, Mo., says the number of caves relates to the geological makeup of this area of the United States.

“It has to do with (the state’s) topography, especially in the southern half of the state and the river by Hannibal, where there’s lots of dolomite and limestone formations. ... An old ocean used to cover the central part of the country,” Mr. Hansen says.

Visitors still can see fossils of shells and other sea life in the walls and ceilings of many caves. He says limestone also is a relatively soft and porous stone, making it prone to water erosion, which is why so many caves appear near bodies of water.

Fantastic Caverns is one of many show caves in Missouri, which are commercial public attractions operated by either state parks or private owners. Most are geared toward families and school groups, so their main features contain lights, railings and walkways that make them easily accessible. Fantastic Caverns is the only ride-through cave attraction, making it a good pick for visitors with physical limitations. For adventurous spirits looking for a more authentic experience, some cave tours conduct lantern tours.

“One of the most historically significant caves in the state is Mark Twain cave up in Hannibal. Its claim to fame is obviously the Mark Twain writings, ‘Tom Sawyer’ and ‘Huckleberry Finn.’ That was one of the early exposures of the public to caves, through literature,” Mr. Hansen says.

“One of the first real cave attractions in Missouri was Meramec Caverns (near St. Louis). ... They’re one of the larger cave attractions in the nation, way up on the list for folks to visit, especially on Route 66. They get a lot of European visitors that are fascinated with Route 66,” he continues.

Other cave attractions worth noting are Marvel Cave, a huge system beneath Silver Dollar City with a main room large enough to fit five hot air balloons; Bridal Cave near Lake of the Ozarks, which is a popular wedding destination due to its attractive stalactite formations; and Robidoux Spring Cave in Waynesville, a popular spot for certified scuba divers.

Of course, not all caves are guided or safe for the general public. If you’re interested in exploring smaller caves near your community, Mr. Hansen says it’s important to make sure you’re allowed on the grounds in the first place. Even in the wilderness, most are found on either private or government-owned ground, so many areas require permits or permission to enter.

Once you’ve determined if an area can be accessed, it’s also vital to take proper safety precautions. Watch the weather forecast and plan on visiting on a sunny day, because heavy rain can cause underground flooding. Mr. Hansen reminds explorers to let other people know where you’ll be and when you plan on being home so they’ll know where to look in case you don’t return on time. Wear warm, protective clothing, shoes with good traction and a sturdy helmet, and bring multiple light sources. Avoid going by yourself, and consider joining a group that can help teach you the ins and outs.

“Probably the best way to do it is to get involved with one of the local grotto clubs. These are clubs of people that have the same interest (in cave exploring). ... It’s easy to find clubs online, that’ll really help them get trained and experienced so they can do it fun and they can do it safely,” Mr. Hansen says.

To learn more about Missouri’s many other cave attractions, go to www.visitmo.com.

Brooke Wilson can be reached

at brooke.wilson@newspressnow.com.

Follow her on Twitter: @SJNPWilson.