If there is any possibility of ambiguity natives will use additional words or paraphraze the sentence to make it clear. If you ask somebody about any park nearby you can say "Где здесь поблизости какой-нибудь парк?" If you meen some specific park that was discussed before you may say "Где этот парк?" If you are telling some story/novel and it starts in some park you may say "В одном парке..."
a small problem, in questions like this, where you are supposed to type in Russian, no Russian keyboard is provided, you do accept phonetic translations as a spelling error, but that doesn't really help with learning Russian, there are off site keyboards, or you can buy a Cyrillic keyboard but both are a hassle to deal with, you could just put buttons with all the Cyrillic letters, though i am no programmer and i don't know how difficult that would be. this is just an idea for future updates.