If you are looking for nature, I recommend Newfoundland. The is ocean, highlands, a few mountains, forest, and a great history! The people here are amazing. I am not from here, but I loved it here so much that I had to move here! Newfoundland is famous for its culture (which is completely different from anywhere else - kind of like Ireland or Scotland a few decades ago), it extremely hospitable people, and it's natural beauty. There are some outport communitites that are abandonned as well as many that seem to be caught in the past. Some you can only get to by boat! St. John's has a great culture and history as well. George Street is the street with the most bars per capita in North America (and man is it awesome.... best place to be on a Friday or Saturday night.... and probably Sunday.... and maybe Monday, Tuesday, Wednesday, and Thursday!), Water Street is the oldest street in North America, and Cape Spear is the most easterly point in North America. The Geo Centre is a museum built down into the rock to show the history of rock and the island. Signal Hill is the place where Marconi sent the first signal across the ocean to England.
If you want to tour natural beauty, there are many different loops or drives you could take along different coasts. In the summer, there is whale watching and ice bergs. You can kayak in the ocean. You can fish in non-restricted ponds across the island. There are always tonns of summer festivals going on across the island.
Well, as you can see, there is a lot that makes Newfoundland an ideal place to visit. Unfortunately, they do not advertise as much or as well asthey should. They are starting to advertise eco-tourism. Check this out:
http://www.newfoundlandandlabradortourism.com/
Where ever you end up going, enjoy your trip to Canada!