East Canada 🇨🇦 Suggestions please!

[SouthCoastShell]

Hi we are at the early stage of planning a trip to East Canada. We are thinking Montreal,Toronto,Niagra falls etc. Any advice on must see places/attractions would be great! We love a mix of city and nature.

We did a 3 week east coast trip to Canada 10 years ago. We started in Halifax and ended in Toronto.

Highlights were Montreal, montmorency waterfall, Cape Breton Island, whale watching off St Andrews, and a week spent 2 hours north of Toronto in the kawartha lakes region. I'd skip Montreal

Nova Scotia is beautiful. I'd also add in Prince Edward Island.

I wasn't massively keen on Toronto, although to be fair I was there for work and not pleasure.

We flew into Toronto, took the train to Ottawa for 3 days, back to Toronto for a week, picked up a car and spent a week in a lakeside cottage, then drove to Niagara for 2 nights. It was a lovely trip although we didn't see much of the proper Canadian scenery, so would love to go back. We did see lots of sports, all the city sights, museums, parliament etc and had dinner atop the CN tower. Niagara was spectacular but not worth more than a day. Lake cottage was awesome, it had canoes and kayaks, fire pit etc.

Ugh - brain fog. Mine should say highlights were quebec city not Montreal.

Thanks for your replys.
We have narrowed it down to 4 days in Toronto (Niagra visit) 3 days at Alonquin national Park then one night at Ottawa ending with 6 days in Montreal.
What would everyone suggest is a must do?

Toronto Aquarium is unexpectedly good. Lawrence Market is over hyped but about a block away so worth doing for lunch. You can stop off at the vineyards for ice wine en route to Niagara if you are heading that way. You should time your visit to Montreal with maple syrup season if you have enough flexibility.

Niagara Falls boat trip
Toronto:
Dinner at the CN Tower - check sunset times and book for an hour before, for daytime, dusk and nighttime views.
Bluejays baseball game
Ferry out to the islands for a stroll or bike ride
Ottawa:
Parliament visit
Any of the museums or gallery, depending on your interest

Tim Hortons (ubiquitous coffee shop chain) for cheap refreshments and donut holes.