Are you US or Canadian side?
The US-side is the town I grew up in. How sad to see it have it gone down hill with the pull out of all those industries (though the rusty works are still abundantly seen).
Also on the US-side, it's a short drive to
Fort Niagara. A french/british fort (depending on the year) since 1726.
In Buffalo, the
Albright-Knox Art Gallery is absolutely worth it.
The primary "industry" on both sides of the border are casinos. On the US-side, the
Senaca Niagara Casino has some new restaurants and a spa (though haven't tried these out yet to see if they are worth it).
On the Canadian side, there are the garish wax museum touristy things which can be fun in a kitsch way. Wineries and some pretty drives are nearby at
Niagara on the lake. If you want, stay or try the spa at
the Prince of Wales Hotel. It's on Conde Nast's Gold List of best hotels in the world.
It could be quite chilly near the falls so bundle up even if it looks like a nice day.