This Missouri cave near St. Louis holds a limestone curtain older than the Atlantic Ocean

It’s Route 66’s underground showstopper

You can drive an hour west of St. Louis on Interstate 44 and drop into a cave system that runs 4.6 miles through the Ozarks.

Meramec Caverns sits near Stanton, Missouri, in a state with more than 6,000 surveyed caves, and it’s the largest commercial cave of the bunch. About 150,000 people walk through it every year.

The limestone inside has been forming for roughly 400 million years, and the temperature holds steady at 60 degrees no matter what’s happening above ground. But the real draw is what’s waiting on the fifth level.

Native Americans sheltered here centuries before gunpowder miners arrived

Long before European explorers showed up, Native Americans used these caves for shelter. Pre-Columbian artifacts have turned up inside.

A French explorer first entered in 1722 and found saltpeter, a key ingredient in gunpowder. Mining crews pulled it from the rock for more than a century after that.

During the Civil War, the Union Army ran a gunpowder operation inside until Confederate troops destroyed it in 1864.

The cave changed hands several times before Lester Dill bought it in 1933, renamed it Meramec Caverns and opened it to the public. His family still runs it today.

A 70-foot stone curtain fills the Theatre Room

The biggest formation in the cave is called the Stage Curtain, and it looks exactly like a giant theater drape frozen in stone. It stands about 70 feet tall.

Mineral-rich water flowed over an inclined rock surface for thousands of years to build it, layer by layer. The cave runs a light show against it at the end of every tour in what they call the Theatre Room.

That formation is the reason the whole place earned its nickname: “The Greatest Show Under the Earth.”

Climb 58 stairs to see a six-foot stone table on three legs

The Wine Room sits on the cave’s fifth level, and getting there means climbing 58 stairs. It’s the only optional stop on the tour, but you don’t want to skip it.

The centerpiece is the Wine Table, a rare aragonite formation that stands about six feet tall on three natural legs. The whole structure formed almost entirely underwater over thousands of years.

Mineral clusters called botryoids hang from the walls like bunches of grapes, which is how the room got its name.

A shallow stream looks 50 feet deep in the Mirror Room

One of the most photographed spots in the cave is a trick of light and water.

The Mirror Room holds a stream only about 1.5 feet deep, but when the guide flips on the lights, the still surface reflects the ceiling so clearly that it looks like a 50-foot drop into a bottomless canyon.

You stand at the edge and your brain tells you you’re staring into something deep. It takes a second to sort out what you’re actually seeing.

Locals danced underground to beat the summer heat

Near the cave entrance, a large room has gone by the Ballroom since the 1890s.

Starting around 1890, people from nearby Stanton hauled themselves underground to throw summer dances and parties where the air stayed cool. The room held a 50-by-50-foot dance floor and packed in big crowds.

You walk through it near the start of the guided tour today, and the space still hosts the occasional concert and event.

Jesse James may have slipped out through the back exit

Local legend says outlaw Jesse James and his brother Frank hid in these caves during the 1870s.

One popular story has a sheriff waiting at the entrance while the brothers escaped along the underground river through a back exit.

In 1941, owner Lester Dill found artifacts in a newly opened section that he linked to James. Historians haven’t verified much of it, but Dill turned the outlaw connection into one of his best marketing tools.

Bumper stickers and barn roofs made the cave famous

Lester Dill knew how to sell a cave. While visitors toured underground, his workers tied small Meramec Caverns signs to the bumpers of their parked cars.

Dill also offered to paint farmers’ barns for free, as long as he could put giant cave advertisements on the roofs. At its peak, his campaign covered barns in 14 states, mostly along Route 66 and other major highways.

About 400 barn signs went up. Fewer than 50 survive today.

Billboards still line I-44 like they did on old Route 66

Meramec Caverns is one of the most recognized stops along historic Route 66. The cave opened to tourists in the 1930s, right when cross-country car travel was booming.

Families heading west made it a regular stop, and that habit stuck. More than 50 billboards still line Interstate 44 pointing you toward the cave.

You’ll start seeing them well before your exit, and they come at you one after another like a countdown.

The 80-minute tour covers a mile of paved underground walkways

The guided walking tour runs 1.25 miles along lit, paved walkways. Tours leave every 20 to 30 minutes throughout the day and last about 80 minutes.

Trained rangers lead you through multiple levels, pointing out formations and laying out the history as you go. Most of the route works for just about anyone, though some sections include stairs and steeper spots.

The tour wraps up with the light show projected onto that 70-foot Stage Curtain.

Ziplines and riverboats keep you busy above ground

Once you come back up into daylight, there’s more to do along the Meramec River. Canopy-topped riverboats run half-hour rides along the water.

A zipline course sends you through the treetops and across the river.

You can grab a canoe, kayak or raft for a 6- or 11-mile float down the Meramec through the rolling, forested hills of the Ozark Plateau.

Kids can pan for fool’s gold, fossils and gemstones in a setup built to look like a 19th-century mining camp.

Blind cavefish swim through a seven-story underground world

The cave system drops through seven levels. The tallest chamber could fit a six-story building inside it.

Formations run the full range: stalactites, stalagmites, flowstone, columns and rare onyx deposits. Many of them are still growing today as mineral-rich water keeps dripping.

You’ll hear the guides tell you not to touch anything, because oils from your hands can stop a formation’s growth entirely.

An underground river flows through the lower levels, and it’s home to blind cavefish and blind crayfish.

Explore Meramec Caverns in Stanton, Missouri

You can find Meramec Caverns at 1135 Highway W in Stanton, Missouri, about three miles south of I-44 exit 230. The cave sits roughly 60 miles west of St. Louis, so it makes an easy day trip.

Tours run year-round and start at 9 a.m. daily. Bring a light jacket, because that constant 60 degrees feels cool after a while.

Close-toed shoes are a good idea for the paved but occasionally steep walkways. Check the official website for seasonal hours and ticket prices before you go.

This article was created with AI assistance and human editing.

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