did-you-kno: The Devil’s Kettle waterfalls in Minnesota have one side that pours over a ledge and continues, and another side with a deep hole that vanishes into nowhere. Researchers have poured in dyes, ping pong balls, and logs, but nobody can figure
tags: So many OTPs, queue,
from: https://eikuuhyo.tumblr.com/post/125159470807