The Cincinnati Zoo is a gun free zone.
This is from The Truth about Knives.com:
You Can Own Anything You Want, But There’s A Catch.
Ohio doesn’t ban the possession of any particular kinds of knives. This by itself would be very rational, but Ohio knife laws are not rational. You can own whatever you want, but that doesn’t do you much good because you probably can’t have it in your pocket outside your own home.
Deadly Weapon=Knife=No Concealed Carry.
Knives themselves aren’t specifically mentioned much in Ohio’s books, because Ohio law simply prohibits the concealed carry of any deadly weapon. It then fails to define ‘deadly weapon’ with any specificity, other than to describe them (and I paraphrase) as ‘things which can kill’ and which are also ‘designed to kill’ or ‘carried as a weapon.’
So, basically, every knife ever made is up for grabs as a ‘deadly weapon’ except maybe a Victorinox Solitaire because it’s too small. The learned minds of the Ohio court system have further muddied the waters with lists of characteristics that make a knife more likely to be considered a ‘deadly weapon.’
This list includes every conceivable characteristic which differentiates a knife from a 19th century slipjoint pocketknife. Under the bizarre and utterly retarded precedent of State v. Cattledge, thumb studs, blade locks, strange looks, sharp tips and serrations are all indications of nefarious intent when it comes to pocket cutlery.
Way To Go,Ohio!
By providing such an elusive, inclusive and ambiguous definition of ‘deadly weapon’, Ohio gives its police and prosecutors absolutely unfettered discretion to arrest and prosecute anyone carrying anything bigger than miniature Swiss Army Knife in their pocket. There are no safe harbor provisions, no blade length guidelines, and no clear indication as to what is prohibited and what is not.
Ohioans will probably say that they’re rarely hassled on the street when it comes to knives, but this will be cold comfort to those of them who will be suffer arrest, confiscation and prosecution for unknowingly stepping over an invisible and constantly-moving line.
Even though it already bans nearly everything, Ohio has no knife law preemption. This allows counties and cities to pass additional restrictions, and many Ohio municipalities enforce a blade length limit of 2.5 inches.
). 
