I just heard a piece of music I never knew existed. Frede Grofe of Grand Canyon Suite fame wrote a Niagra Falls Suite on commission from Niagra Falls Power Company. One of the movements is called "the honeymooners".
The things you learn later in life.
Some choices for Niagara Falls, USA weddings include:
The Falls Wedding Chapel
240 Rainbow Blvd.
This company offers a variety of settings and packages. One option permits the bride and groom to exchange vows on the edge of the falls; another features a helicopter wedding.
Flight of Angels
You can say your vows aboard this tethered helium balloon, 400 feet above the earth for a bird's eye view of the falls. The balloon can be chartered for private weddings.