EXPLORING DOWN UNDER

The problem with summer is that it is hot.

Deep under the ground, though, the temperature is a constant 57 degrees. And there are a number of places in Missouri you can spend some time underground.

Missouri has more than 5,700 caves, with an average of 125 being discovered every year, according to the Missouri Department of Conservation. About half the caves are mapped, and about 20 are open to the public.

The most experienced amateur cave explorers call themselves cavers. The rest of us are just spelunkers.

One of the spelunking sites closest to Cape Girardeau is Onondaga Cave State Park near Leasburg.

The entrance to the cave is through a red-lit airlock in the park office, but even that close to the surface you can see brown bats hanging from the ceiling as the raked concrete path leads you down.

From there, you enter a dark world in which electric lights briefly show the whites and reddish browns of calcium and iron.

The stone features in caves, called speleothems, are made by water seeping through ground and rock and dripping through the ceiling of a cave. The water leaves mineral deposits behind over hundreds, thousands, millions of years.

But from this process, an amazing variety of shapes arises.

The ceiling of Onondaga Cave appears fuzzy at a distance because of hundreds of soda straws, so-called because of their shape. They're clustered especially along the Lifeline, a crack in the ceiling hundreds of yards long. When mineral deposits block up the straw, the rock builds on the outside of the stalactite.

Stalagmites, on the floor of the caves, are usually blunt and more rounded, the younger active ones at Onondaga looking like thick white candles cupped by a few hours of burning. When water no longer drips them, stalagmites turn dark and stop growing. The oldest stalagmites in Onondaga are called the Twins, two stubby pillars of stone taller than a man. The guides say that it takes 100 years to make a cubic inch of speleothem.

When top and bottom meet, it is called a column.

Then there are cave grapes, cave popcorn and cave drapes, all named because of how they look. The ribbed and wavy formations sometimes look like giant fungi.

The dripping action in the pools of the Lilypad Room made the stalagmites splay outward, giving the room its name.

Some formations are huge. The Queen's Canopy, a waterfall of white calcite, could contain a couple of small houses. It still looks huge when viewed from across the cavern room, a football field in length.

Visitors are reminded several times not to touch the stalactites and stalagmites because the salts and oils on the skin can stain or deform them. One you can touch at Onondaga, though, is a blackened point that hangs over the path. It's been dubbed the Rock of Many Names, guides say, because a lot of people hit their head on it as they walk by.

The Rock of Many Names feels like ... stone. Cold stone.

Not far from Onondaga is Fisher Cave at Meramec State Park near Sullivan. Fisher Cave has a lot of stalactites, but most of them were broken off in years past by people who took them to use as lawn ornaments. Unfortunately, the same process that built them dripping water destroyed them, according to park naturalist Jeff Durbin. They dissolved in the rain.

People also used the cave to hold summer dances before the advent of air conditioning, Durbin said. They could dance three or four hours before the smoke would get too bad.

Unlike Onondaga with its high vaulted ceiling, you can get a close look at Fisher Cave's soda straws as you hold up your lantern to a low-hanging outcropping. A tube of stone, filled with cold water about to drip.

Most caves require some physical effort, whether it be walking hunched over for 100 feet in Fisher Cave, walking with care on the steep, wet paths of Onondaga. The exception is Fantastic Caverns near Springfield, which offers mile-long tours only in a jeep-drawn tram, no walking required.

On the other end of the spectrum, Devil's Icebox Cave in Rock Bridge Memorial State Park near Columbia offers strenuous tours that are either four or eight hours long. But spelunkers as well as cavers can go.

Even at Onondaga's deepest point, 250 feet below the ground, the cave still seems spacious. But if that's still too closed in, there's Grand Gulf State Park, a few miles inside the southern Missouri border near Thayer. Most of the roof of the cave, three-quarters of a mile long, collapsed about 10,000 years ago.

The best vantage point is near the start of the trails, where a wood deck juts out on part of the uncollapsed roof. Here you can best view the chasm. The east side is populated with spindly trees, while much of the west is draped in green, veined by rain gullies.

Although open, Grand Gulf presents its own form of being closed in, for the treetops will rustle with a wind that cannot be felt on the ground. As you follow the stairs of wood plank and steel grating down to the bottom, the wall of the canyon to your left juts out, the angular outcroppings of stratified rock giving you the impression of the weight of millions of years.

At bottom, water condensed out of the air drips from a mossy outcropping, like the constant dripping in Onondaga. But the speleothems are long gone.

And, unfortunately, it's hot.

IF YOU GO

Missouri caves have different seasons, schedules and admission prices. Some may require appointments. It is best to call before planning any trips. Some of the more accessible caves are:

Onondaga Cave and Cathedral Cave

Leasburg

(573) 245-6576

Fisher Cave

Sullivan

(573) 468-6072

Meramec Caverns

Stanton

(573) 468-3166

Fantastic Caverns

Springfield

(417) 833-2010

Ozark Caverns

Linn Creek

(573) 346-2500

For a complete list of Missouri caves open to the public, go to www/umsl.edu/~joellaws/ozark_caving.