Lived there for a while and the obligatory spots to take friends that visited included the Falls,the power station on the Robert Moses Parkway, Fort Niagara at Youngstown, the shops of Lewiston, the Fatima Shrine if they are religious, with perhaps a side trip over to Canada [Horticultural Garden, Niagara on the Lake]. Rides on Maid of the Mist are sort of traditional but it’s basically a shower with river water and looking up at a lot of water coming down. Lot of orchards in the area to get fruit, apples particularly.
If you do go over to Canada , have your passport up to date. The Canadians are pretty easy to work with, but the US Border Guards are oh so dedicated.
That's right. Unless you're an illegal alien.....
However, it is far easier to get out of the US than in if you're a citizen.
Either have a passport, a passport card, or enhanced drivers license.
You might want to check with the US immigration website about what's needed to get back into the US if you don't have any of those three.