Take a hike up Schunnemunk Mountain and visit the Megaliths. After taking in the sights (on a clear day, at least), you can have some fun scrambling around and finding a cache.
Be sure to wear appropriate clothing and be prepared, for it can be windy and not as warm as lower elevations. On a hot summer day that might be welcome.
Could it be a pickle to get to the cache, yep, I suppose so. And no you will not find any beer, unless you bring your own! Pickle & Beer refer to the bait my good friend cornfarrell used to get me to climb the "liths" that surround the cache container. I hope you enjoy the adventure.