Image copyright Getty Images Image caption The Gay Head Lighthouse in Massachusetts is being moved to avoid falling into the sea.

A US lighthouse will begin a journey inland on Thursday to avoid falling down an eroding cliff side.

The $3m (£2m) effort will move the 400-tonne Gay Head Lighthouse in Martha's Vineyard, Massachusetts.

The 160-year-old structure helped mariners navigate foggy coastlines during the peak of the whaling trade in the region in the 1800s.

The historic lighthouse should arrive at its destination farther away from the Atlantic Ocean by Saturday.

As it stands now, it is only 46ft (14 metres) from the edge of a cliff.

Image copyright Getty Images Image caption Workers have been preparing the historic lighthouse for its move.

Gay Head Lighthouse is a popular tourist destination for holidays, on the western side of Martha's Vineyard.

The lighthouse has been hoisted off the ground to prepare for the move.

The lighthouse will be passed along steel beams and rollers by hydraulic jacks, which will move it 129 feet (39 meters) southeast of its current location.

Image copyright Getty Images Image caption Strong ocean waves have distorted nearby Gay Head cliffs

Within two years, the lighthouse would have been too near to the edge to move safely.

The call to move it has become more urgent in recent years due to landslides, strong ocean waves and groundwater, eroding the surrounding Gay Head cliffs.