I was working on underwater rules that would be both (a) useful and (b) simple when I came across this photograph. Although the explanation for this ladder is probably pedestrian, it evokes in me a deep sense that something is down there. Something strange or magical or enigmatical or terrifying. But something.
You’ve got a ladder leading down into a placid pool of endless blue-green. Small waterfalls babble and crash through the quiet confines of the emerald forest.
So you tell me: What’s down the ladder?
My knee-jerk reaction is something hideous, cthonian, and evil. Something that previous people here used to go down to placate. But now they are gone, and you are left with this serene beauty, a lurking evil, and no one left who knows how to make it stop.
Judging from the ladder, whatever it is apparently turns metal into stone.
Go down it enough and it starts going up … and out … another pool … in another world.
A fey touched paradise.
I can see the finger monster from the recent goblins comic crawling up that ladder during every new moon to take its pleasures upon the surface world.
Ancient mermaid rum-runner hideout.
The bottom of a former quarry, where miners discovered ancient runes that keep shut a very old tomb/vault.
A large room created by a magical bubble of air at the bottom of the pool. If you swam down to it you would fall through the bubble to the floor and once you were in the room you would have difficulty getting back up to the water, hence the need for a ladder going both ways.
What’s down the ladder?
Only one answer – Adventure!
A drain plug. Pull the plug and the rest of the pool drains, put it back and the pool fills up again. But maybe someone hid something down there…