It takes characters from 1st level to 20th level.
You'll not find a better value for that kind of campaign anywhere else.
ASEO out
Forgive me in advance for asking a noob question, but the small preview on this web site for the Shackled City doesn't list a level range. What is the expected level range for characters going through this adventure path? Thanks!
1st through 20th, if you run the entire Adventure Path.