Drive N, along the Gorge on the Canadian side, to Niagara on the Lake. It's about 6-7 miles N after you go under the Lewiston/Queenston bridge.
It's quaint (I know quaint = $$$) but if any of your guests are female they will like it. There are a bunch of nice restaurants there, and their "Main Street," and the streets between there and the River, is a nice walk, depending on the weather of course.
It you go in the Summer, the Jet Boats on the river are great!