The locks of the Rideau Canal.  To the left you can see the Chateau Frontenac.

When I was a kid, my grandparents lived in the middle of nowhere, but near a section of the Trent Severn Waterway.  Since then, I’ve been fascinated by locks.  The locks I’m talking about basically allow boats to travel upwards or downwards, where one body of water is physically higher than the other.  A better explanation can be found here.