How many letters does the top answer for “city in wales” have?

The most common answer is swansea (7 letters).

Crossword clue: city in wales

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

swansea 7 letters wd-fact-v3

a port city in southern Wales on an inlet of the Bristol Channel

a port city in southeastern wales 50% similar → newport

city in new south wales 50% similar → albury, armidale, bathurst

the capital and largest city of wales 50% similar → cardiff