This is a double negative. Whenever you see a double negative you need to think of it as a positive.
'Nor,' and 'without,' are both negatives. So 'nor is the city without,' means that the city DOES have moments of beauty.
If only one negative was used in the sentence it would have the opposite meaning:
A) Nor does the city have moments of beauty = the city has no moments of beauty.
B) The city is without moments of beauty = the city has no moments of beauty.
C) NOR is the city WITHOUT moments of beauty = the city has moments of beauty. (Capitals used for emphasis).
In English two negatives, such as nor and without cancel each other out.
'I don't think that I wouldn't consider going there,' = I would consider going there.