Great area to visit if you want some amazing pictures and a hiking trail. There is parking up ahead at the Pololū Valley Lookout where you can take pictures and even venture down to the water via the Pololu Trail. After you're done visiting; there is a neat little turn out on the way back that gives a nod to the history of the area. The actual historic mule station site is closed but no need to go in; should be an easy park and find on the way out.
Kohala Ditch, which was built in the early 1900s to carry water from the mountains to Kohala Sugar Plantation's cane fields by the coast. Two hundred mules were brought in to transport workers and materials to the construction sites of the irrigation system, a remarkable 22.5-mile engineering feat consisting of open ditches, flumes and tunnels.