Cape Cod’s oldest lighthouse, locally known as the Highland Light, is officially named "Cape Cod Light" on the NOAA nautical chart for the region.
The Highlands of Truro have been steadily eroding since 1797. When Thoreau visited Highland Light in the 1850's, he wrote in "Cape Cod" about the extensive erosion of the cliffs fronting the lighthouse. In 1990 only 128 feet of the original 500 foot setback remained. In July of 1996, when the Highland Light was only 100 feet away from the edge of the cliff, the lighthouse was moved to its present location. The International Chimney Company of Buffalo, New York lifted the 430 ton lighthouse, and pushed it on steel "I" beams, lubricated with Ivory Soap, 453 feet to a safer location. The $1.54 million dollar cost was shared among the Commonwealth of Massachusetts, the United States Coast Guard, the National Park Service, and the Truro Historical Society.
Information Source: http://www.capecodlight.org/