Translation:Alexandria is a historic coastal city.
Again: when you translate the adjective in the same order as in the sentence, it should be correct. So: coastal historic is the same as historic coastal
Duolingo is consistent on this one: Arabic adjectives are in the reverse order of the English ones. pretty new house = bayt jadid jamil (so new/jadid is next to house/bayt, and pretty/jadid is the furthest away)