The reclaimed land was once used for salt production, using local coal.

Preston Island, south of Low Valleyfield in the Firth of Forth, was reclaimed by Sir Robert Preston, 6th Baronet in the early 19th century.

[2][3] Two further coal shafts were in development when a fatal firedamp explosion occurred in 1811, after which the mine was closed.

[2][4] Salt production continued for some decades, under lease from Preston.

The 'island' is no longer surrounded by water, following further land reclamation, using ash from the nearby Longannet power station.