Sure you can carry anywhere you damn well please. Is it legal or not? that's a different question. City parks, as far as I know, have no binding restrictions. But if it is posted and someone sees it and you are asked to leave you better do it. However if I decide to go for a walk in that park wearing a dress, heels and a feather boa wrapped around my neck you better not say a word or I'll have you arrested for a hate crime.