Left route before wrong turning in Welsh town (8)

I believe the answer is:

llanelli

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

'welsh town' is the definition.
(I've seen this before)

'left route before wrong turning' is the wordplay.
'left' becomes 'l' (common abbreviation).
'route before' becomes 'lane' (type of road. I am not sure about the 'before' bit.).
'wrong' becomes 'ill' (I've seen this in another clue).
'turning' is a reversal indicator.
'ill' written backwards gives 'lli'.
'l'+'lane'+'lli'='LLANELLI'

'in' is the link.

Can you help me to learn more?

(Other definitions for llanelli that I've seen before include "Welsh town" , "Welsh place" , "Town NW of Swansea" , "Port in Dyfed" , "Carmarthenshire town; an ill ell (anagram)" .)

I've seen this clue in The Times.

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.