Providence Canyon, a couple of hours' drive from Atlanta,
is known as Georgia's Little Grand Canyon.
This network of gorges and gullies reaches over 40 metres deep, and it's beautiful.
Even without the artificial saturation boost that a lot of photographers give it.
This is known as one of the Seven Natural Wonders of Georgia.
There is just one problem with that description, though:
this is man-made,
by accident.
This is a scar in the Earth,
and it's a scar that'll take a very long time to heal.
The ground here is made of unconsolidated sediment.
That means I'm standing on loose sand and clay that was deposited
tens of millions of years ago on what was then the sea floor.
It's stable, of course,
but it's never been compacted into solid rock or cemented together by geology and time.
It's not going to collapse,
but if you draw a line from, say, desert sand, where nothing sticks together,
to solid rock, the sort of thing that miners have to blast with dynamite...
the ground here is definitely on this end of the scale, for a long way down.
Tree root systems, grass, and other plants all help to stabilise it.
And that was fine for millions of years, and through most of human history,
until settlers manifested their destiny all over this continent.
At the start of the 19th century, this whole area was flat forest,
none of these canyons were here.
Settlers cleared the area of all its trees and ploughed the soil for agriculture.
Either they didn't know about crop rotation and soil management
or perhaps they didn't care, seeing a whole continent laid out before them.
Soon, the little drainage paths that rainwater took after storms started to erode
and become bigger, and bigger, and... bigger.
With soil like this, it only took a few decades before this landscape formed.
A century and a half later, new trees are starting to stabilise some of it,
but it's still changing and eroding.
The park management has to move these fences occasionally;
sometimes they'll find that one of the spires out there has just fallen after heavy rain.
There are strict no-climbing warnings here, because, well,
the rock you're holding onto could just fall away and dissolve in your hand.
So my question is: should this count as a natural wonder?
It is part of nature.
People do come to wonder at it.
All those colors are from the different minerals that are in the soil:
so this is a look back through those millions of years of geological history,
and those millions of years are unquestionably natural.
But exposing them: that was very much human.
[rumbling noise]
So I'm hoping the microphone picked up that noise.
Er, because as soon as I turned my camera off,
there was a massive noise, and I'm fairly sure that was a rockfall.
From this cliff.
Which is worrying.
It's probably fine. It's probably fine.