That's what the locals call it, though the actual length is 3850 feet. Opened 1910.

I spent the afternoon poking around. It was warm today, but standing in front of this opening is like standing in front of a giant AC unit. It's said to be haunted by the ghosts of two workers killed during the tunnel's construction. They are seen to be working with shovels. I walked in a good thirty feet and wasn't scared at all...

The track still gets some use by short freights carrying scrap metal or oil from Plainville to Waterbury.