Did you know that there were abandoned tunnels behind Niagara Falls? No, not the ones that you go through when you pay for the trip on the Journey Behind The Falls attraction. The tunnels I'm talking about are even more mysterious, completely hidden from the naked eye, and very cool.
Read the full story (with more images) here.
To give a sense of scale here's the cross section diagram of Niagara Falls.
More info here on the Niagara Falls Power Company.
