In central Kentucky, the Mammoth Cave National Park is not only a geological wonder that is unequaled in scope, it is also a great getaway for a long RV weekend, with a terrific campground, beautiful scenery and bike paths through a heavily forested area of gently rolling hills and the lush Green River valley.

Located 15 minutes off I-65 at Cave City Exit (Exit 53) or Park City (Exit 48), the park encompasses 53,000 acres. But it is the 400 miles of caves beneath the surface that make it so dramatic, the largest such cave system in the world. It is probably even bigger. Cave explorers believe there are a couple hundred more miles under there still to be discovered.

We visited the park in late August and the crowds were way down. Our ranger-led tour had 10 people. Just a couple weeks earlier, before school resumed, the same tour routinely had as many as 120 visitors.

The vast chambers and complex labyrinths as deep as 250 feel below the surface are amazingly accessible, though visitors should be in reasonably fit condition. There are lots of steps – our tour of the New Entrance part of the cave starts with 243 steps straight down, on very narrow metal stairways built for the park service by a company that specializes in designing stairways for the cramped quarters on submarines.

The New Entrance to the Mammoth Cave system is a lot older that it sounds. First excavated in 1921 and enlarged and enhanced repeatedly through the years, it begins with a bus ride over the top of the cave to the New Entrance. An path works its way to the bottom of a depression – an old sinkhole, really – and ends before a steel door.

From there, you enter the cave, heading down the stairs, winding around huge rocks and sandstone formations, sometimes only a couple of feet wide. The tour includes a dramatic series of domes and pits, large trunk passageways, and a short journey through dripstone formations. You see and learn about stalactites (deposits that drip down from the ceiling) and stalagmites (deposits that rise upward from the floor) and view an impressive formation dubbed “frozen Niagara”that looks indeed like a frozen waterfall.

Our tour lasted about two hours. My favorite time came when, deep underground in a wide cavern, the ranger turned out the subdued lighting that illuminated the pathways and walls. Total, complete darkness ensued, so dark you could not see your hand in front of your face. The ranger had everyone sit still and be silent. There was total silence, too. I swear I could hear my heart beating, the blood running through my veins. I know, I have a vivid imagination.

This was just one of a several cave tours offered by the park service. It covers not quite a mile and goes up and down about 500 total steps. It has a constant, year-round temperature of 54 degrees.

As we left the tour, we had to walk over a special decontamination platform that looked like a soft treadmill. That’s to sanitize out shoes and help prevent White Nose Syndrome, a fungus that has resulted in the death of over 5.5 million bats in the eastern United States.

I saw only one bat in the caves, though 40,000 or so are said to live in the complex.

We wish we had at least another day or two to have stayed at the park. We would have done all the other tours, as well.

We had Tai, our Norwegian Elkhound, with us the day we visited. For $2.50, we were able to rent an outdoor kennel for him. We brought his water bowl and he had ample shade and actually, after a couple of yips when we walked away to go on the tour, seemed to enjoy it.

We also visited the 105-site campground, just a quarter mile from the visitor’s center. Each site offers a paved parking area, a picnic table, and a fire ring. The campground has restrooms, fresh water, a dump station, garbage dumpsters, and a recycling station.

Only three of the sites have hookups. For the others, there is no electricity or water.

If you want full hookups, the routes to and from the park off I-65 have numerous commercial campgrounds.

We’re seriously considering a return visit in early October when the hardwood forest around the park will be in full color. We’ll take out bikes, though bike rentals are available from the front of the campground store.

*Spelunking anyone?

*spelunking – Exploring cave systems, sometimes called caving or potholing