With a population of about 3 million people, Toronto is not only the biggest city in Canada, but also the fastest-growing urban centre in North America.

Its downtown core is a hub of activity but venture just a couple of kilometres northeast and you’ll find yourself in the Don Valley Brick Works, a former quarry that over the course of three decades has been transformed into a wetland. Fringed by houses and high rises, the marshlands and the valley that surrounds them are home to ducks, foxes, beavers and even the occasional deer.

The urban oasis is one of several spread across Toronto, which was recently recognized by the United Nations Environment Programme (UNEP) as a model for other cities aiming to restore their natural spaces.