The Don Valley Brickworks in Toronto is a pretty interesting place.  Among the various exhibits and things to see is this large one depicting the Toronto watershed.  The various rivers, streams, creeks and underground rivers are shown flowing through the city.  The green spaces or bush areas are the mossy bits on the exhibit, the major roadways are also indicated.  Apparantly it's a way more cool exhibit in the summer as all the water parts - rivers, streams, creeks and underground rivers - have water streaming down them.