The western tip of the Isle of Wight peters out in a series of three jagged rocks known as the Needles.  You might think they owe their name to their sharp edges but it turns out there used to be a fourth, needle-shaped, rock called Lot’s wife, as shown in Isaac Taylor’s map of Hampshire published in 1759.  It crumbled into the sea in 1764, but the name stuck.

What are the Needles made of?

They’re part of a band of chalk running across the Isle of Wight to Culver Cliff in the east, and part of the extensive chalk formation of southern England.  The near vertical strata of the Needles show how strongly the formation was lifted here, around the same time as the Alps were forming.

This map is from Ian West’s site about the geology of the Isle of Wight.