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

The most common answer is birgu (5 letters).

Crossword clue: city in port region

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

birgu 5 letters wd-fact-v3

valletta 8 letters wd-fact-v3

the capital of Malta; located on the northeastern coast of the island

zabbar 6 letters wd-fact-v3

city in afar region 50% similar → asaita

city in amhara region 50% similar → bahirdar

city in andijan region 50% similar → xonobod

city in ashanti region 50% similar → agogo, kumasi

city in attica region 50% similar → classicalathens

city in bukhara region 50% similar → zarafshon

city in capital region 50% similar → seltjarnarnes

city in diana region 50% similar → antsiranana