My plan is to pick up a fellow spelunker (my son) from BNA and head to the Sleep Inn & Suites in Cave City.
I've been off the supercharger network for quite some time now and the more remote I go, the more my charge options dwindle. It doesn't concern me though as I approach the challenge much like a treasure hunt.
I have 59 miles of charge left upon arrival and as I approach the hotel, I mention "I'll add more charge tomorrow... a RV park is 3 miles down the road". We pull into the hotel parking lot and my son spots this 120V circuit at the front of the building. Score! Although I pull only 4 miles/hr., I get an additional 50 miles by morning!
Mammoth Cave is the world's longest known cave system spanning some 400 miles. They don't stretch in one straight line however, but intersect and run above and below each other like a big but shallow platter of spaghetti.
Although our family is more accustomed to caving on our own, this is not allowed here and so we sign up for two guided cave tours; the historic, and the domes & dripstone tour.
Limestone caves like Mammoth Cave are formed by water eroding rock over long periods of time. Raindrops pick up carbon dioxide as they fall through the air. The slightly acidic water now starts to dissolve the limestone as it seeps through cracks in layers beneath the soil. Over thousands of years cracks grow big enough for a person to crawl through. Over millions of years, these cracks become huge passageways. A protective "cap" of harder sandstone acts as a roof protecting the tunnels and passageways.
All kinds of cave critters live here. Some exhibit amazing adaptation to life in the dark. Eyeless cave fish live in deep streams surviving up to 2 years without food and have no need for eyes or coloration.
The park system use to have an aquarium in the cave where visitors could view these fish, however someone complained that National Parks were not allowed to keep animals in captivity, thus the fish have been returned to the depths, exactly the place where we plan to be again tomorrow.