How to get the entire recursive directory structure of an FTP site using wget

How can I use wget to get a recursive directory listing of an entire FTP site?

yes, wget --no-remove-listing ftp://myftpserver/ftpdirectory/ will get and retain a directory listing for a single directory (which was discussed here)

but, wget -r --no-remove-listing ftp://myftpserver/ftpdirectory/ will recurse and download an entire site

so, if you want to get the recursive directory structure, but not download the entire site, try wget -r --no-remove-listing --spider ftp://myftpserver/ftpdirectory/