I keep hearing that about Ottawa - and it's certainly true that it's a long course and in use annually..... but there is a track in the Netherlands that is nearly 200km long..... the problem is that it doesn't freeze enough every year (though it used to..... global warming?)
It's called Elfstedentocht - check Wkipedia...... http://en.wikipedia.org/wiki/Elfstedentocht
It's called Elfstedentocht - check Wkipedia...... http://en.wikipedia.org/wiki/Elfstedentocht