Mimico Creek runs almost in my backyard. The stretch between Lake Ontario and Bloor Street is accessible with several walking trails, but only passable in the winter, when large parts of the creek is frozen so you can walk along the ice.
Most houses which backup on the creek are not even visible in the summer through the foliage, but in winter time, the views are unobstructed.
These concrete slabs were probably dumped into the creek, when someone redid their driveway. In time, these will blend more with the scenery.