I did leave some questions in the images about some of the buildings and places in Niagara Falls and Niagara-on-the-Lake, so please feel free to respond!
Well, let's see. Yes, that is Fort Niagara in your pictures.
The old, old building you saw from the Maid of the Mist is the old Ontario Power Generating plant. Ironically, there is a falcon nest in one of the windows, although it is believed that they used a different nest (never found) this year and produced at least one offspring.
The people in yellow raincoats climbing the stairs are on the Cave of the Winds tour. They do not actually go behind the falls (although early in the last century they did). Too bad you didn't visit the American side. I prefer the Cave of the Winds to the Maid of the Mist (although that's really cool, too!) The American side has more "up close & personal" views of the falls.
My husband & I got engaged at the end of Three Sister Islands that you reach by going over the bridge to Goat Island that you didn't go on.
The covered Jet Boat is for wusses! The open boat is the way to go! What a ride!
birdmusic (who used to be a tour guide at the Falls (NY) during her college years and never, never got tired of seeing it!)