Ted's Caving Page

Ted's Caving Page (also known as Ted the Caver in some parts of the internet) is a Web Serial Novel detailing the attempts of spelunker Ted and his two friends to explore a strange, undiscovered portion of a local cave. Ambiguous horror ensues. First published on the Angelfire webhosting service in 2001, this story was an early example of using the Internet to tell a horror story Blair Witch-style, and remains pretty effective to this day. It can be found here.

Tropes used in Ted's Caving Page include:

Being Watched: ...But by what?
Bolivian Army Ending
Catch Phrase: "I was pumped!". He also seems fond of calling things "bizarre".
The Big Guy / Handicapped Badass: B.
Crazy Prepared: Of course, Ted and his buddies are spelunkers; this comes with the territory.
Dug Too Deep
Evil-Detecting Dog: B's Jack Russel terrier, Whip. To quote Ted, "I have seen her square off with dogs twice her size, but now she acted as if Satan himself was lurking in the darkness."
Genius Loci: Maybe.
Hand in the Hole: How the whole thing starts.
Hell Is That Noise: An in-universe example. Says Ted of the mysterious scream, "I would say it sounded like a cross between a man screaming in fear, and a cougar screaming in pain".
I Don't Like the Sound of That Place: Invoked, as Ted names the passage that they discovered "Floyd's Tomb". As if that weren't ominous enough, it's named after caver Floyd Collins, who died after getting himself caved in.
It's Probably Nothing: Ted and B dismiss the creepy rumbling from inside the cave as trucks driving on the nearby highway, and later, rushing water. It's neither.
Oh Crap: IT'S PULLING THE ROPE BACK INTO THE CAVE.
Plagiarism: Inverted (?). A bizarre rumor spread after this story's popularity grew that it was stolen nearly word-for-word from a short story written by Thomas Lera called Fear of Darkness from the eighties. As it turns out, the story never existed until after Ted the Caver became widely known, and is simply Ted the Caver with the prose cleaned up to be a little more "scholarly" and a stereotypical ghost-story ending tacked on. Lots of people, sadly, bought it hook, line, and sinker.
Primal Fear: Go ahead, read the bit about being in total, pure darkness, and see if you don't get at least mildly creeped out.
Shout-Out: Ted explicitly compares the hieroglyphics deep within the cave to The Blair Witch Project.
Stylistic Suck: The story does a very good job of looking like an ordinary Angelfire page from the early 2000s (because that's exactly what it is).
Ultimate Evil: It's obvious that there's something down there that doesn't want to be disturbed, but what it is, we never find out. Ted briefly mentions an old myth regarding the Hodag, a creature that dwells in caves, but nothing much comes of that.
You Look Like You've Seen a Ghost