20+ years ago I saw the "slag pour" in Sudbury, Ontario. This is molten rock leftover from processing metal out of ore being just dumped down a hillside from special train cars. At night it's really cool:
(from http://www.mysudburyphoto.com/slag-pouring/inco-pouring-slag-PL356.php)
I found YouTube videos from as recently as 2005, yet Wiki travel claims it stopped in the 90s. Who's right? I have a family member going to Sudbury in a few weeks, and if they could safely and legally see a slag pour, I would love to make that possible.
Using an aerial view on Bing maps, I can see what is clearly a train track with slag billows from it, near Road 55 which is mentioned in the articles saying you can't see it any more. I can't seem to see where it happens now. They used to dump a train full (12 cars) every hour, and I doubt that has reduced much, so it must be happening somewhere, right?