One of the oldest state parks in New Jersey, Washington Rock was originally purchased in 1913 to commemorate the historical events of 1777. Situated on top of Watchung Mountain in Green Brook Township, the park is best known for its scenic vista and historical significance. The park is a popular site for picnicking and relaxing.

The strategic location of Washington Rock made it a valuable lookout point during the American Revolution for General George Washington in June of 1777 when the British army under General William Howe was moving toward Westfield. From the vantage point of this natural rock outcropping, General Washington had a thirty-mile panoramic view of the valley and was able to instruct his troops to circle behind Howe?s troops and cut off their retreat.