UNIX for Dummies Questions & Answers

I am trying to loop through folders and extract the name of the lowest level subfolder

I was running the script below, it returns
/bb/bin/prd/newyork
/bb/bin/prd/london
/bb/bin/prd/tokyo

I really want
newyork
london
tokyo

I couldn't find a standard variable for the lowest level subfolder, does something like that exist? If not what is the best way to through away everything in front of the last /

Code:

 for dir in /bb/bin/prd/*
       do
         (echo $dir)
 done