Which article to use for a plural-nominative-feminine noun auf Deutsch?

Question

I want to say "one of the smallest cities".

Answer 1

The article in the sentence you quote is not nominative but Genitive. In any case, the articles in the plural in German are the same for all three genders for all cases: so "One of the smallest cities in Europe" is "eine der kleinsten Städte Europas" (literally: one of the smallest cities OF Europe), where both "der kleinsten Städte" and "Europas" are in the Genitive case.

Answer 2

dunno, but the "eine" is nominative singular feminine and the "of the" is genitive plural.

I'm thinking eine der but I'm usually wrong.