You're looking for a green bison nano cache. It is situated on a metal band behind the top sign near the button for the crossing signal.
Please be aware of muggle activity since this is a public park, and can be come saturated at any time.
The cache is located OUTSIDE of the park, which allows it to be accessed at anytime of the day. Please do not enter the park after posted times/hours as this is not good caching etiquette. Dogs are also not allowed inside of the park, but are welcome if you are passing by when grabbing this cache.
As always, please replace the cache as found or better to keep it from being muggled.