The Rideau Canal in Ottawa is pretty amazing.
Because it gets so cold in Canada the canal freezes up and what you get is a massive ice skating rink that is over 2km long in distance.
My skating improved a lot just having the space and speed to really fly along.
This was my favourite travel experience ever
I made a rather shaky video to remember the experience, but I wobbled so much holding the camera it just makes me feel sick.