The alum works at Kettleness has completely transformed the promontory jutting out into the North Sea. It resembles a moonscape where nothing much grows even after the 150 years since the last alum was produced. Work started in the early 18th century. There are few remains. Much have been lost to the sea. It is only a matter of time before this seeping tank disappears.
Alum is the sulphate salts of aluminium and potassium. It had many uses. From tanning and fixing dyes to medicine. The Greeks and the Roman used naturally occurring alumen. By Elizabethan times production was a closely guarded papal secret. The story of alum in the North East is full of intrigue and espionage.