London location that has one in a pickle? (7)

I believe the answer is:

gherkin

I'm a little stuck... Click here to teach me more about this clue!

'a pickle?' is the definition.
(I know that pickle can be written as gherkin)

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for gherkin that I've seen before include "La traviata composer" , "Cucumber - London skyscraper" , "Immature fruit of cucumber" , "Small cucumber, usually pickled" , "Salad vegetable - City of London skyscraper" .)

I've seen this clue in The Sun.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.