This is the 14525th most frequent Russian word.
парков
"Парков" is the genitive plural form of "парк," meaning "of parks."
The word "парков" is in the genitive plural form, indicating possession or quantity, in this case referring to 'many parks'.
В городе много красивых парков.
There are many beautiful parks in the city.
Here, "парков" is again in the genitive plural form, used after the preposition "по" to indicate "through" the specific objects mentioned.
Мы гуляли по аллеям парков весь вечер.
We strolled through the alleys of the parks all evening.
In this instance, "парков" is used as part of a possessive phrase in the genitive plural to describe what is being developed.