1)
Where did they build?
1.
Rashi: Everyone built next to what the previous one built, until the wall was completed. So was the custom. V'Al is near, like "v'Alav Mateh Menasheh." Sometimes it says Al Yado, and sometimes Alav.
2.
Malbim: Between Migdal Chananel and Sha'ar ha'Dagim.
