The Hudson River Cliffs, also known as the PALISADES, are a series of steep cliffs along the western shore of the Hudson River in New York and New Jersey. The cliffs stretch for about 80 miles and reach heights of up to 500 feet. They were formed by the erosion of the river over millions of years and are composed of diabase, a type of igneous rock. The PALISADES are a popular tourist destination, offering spectacular views of the river and the surrounding area.