St. Joseph North Pier Inner and Outer Lights, Michigan © Kenneth Keifer/Getty Images

Amid dusky hues, lighthouses mark where a Great Lake meets a river. Two piers were built on Lake Michigan, one either side of the mouth of the St. Joseph River to help protect ships sailing upstream. In the early 20th century, a lighthouse was built at the end of each pier; the St. Joseph North Pier Inner and Outer Lights, pictured here.