This directory (and version of CentOS) is depreciated.  

CentOS-4 is now past EOL

You can get the last released version of centos 4.9 here:

http://vault.centos.org/4.9/

Please NOTE:  this is not being maintained for security since moving to Vault.
It will have security issues, you should upgrade to a new version instead.