Chatham Lighthouse, known as Twin Lights prior to 1923, is a lighthouse in Chatham, Massachusetts, near the "elbow" of Cape Cod. The original station, close to the shore, was built in 1808 with two wooden towers, which were both replaced in 1841. In 1877, two new towers, made of cast iron rings, replaced those. One of the towers was moved to the Eastham area, where it became known as Nauset Light in 1923.