I believe that, if the emphasis is whether or not there are parks, then the Hungarian word order would be different. Vannak ott parkok? = are there parks there? Vannak parkok (ott)? = are there parks there?
Are there parks? = Vannak parkok?
The "there is/are" contruction typically means existence.
The second word "there" is more than redundant. "Are there parks?" is more than enough, too.