linux - Hard symbolic link directory

I am taking over control of a server and I have found a directory in two different locations:

/var/www
/home/user.name (i.e., ~/)

that have the exact same inode number:

ls -i
11895253 directory.name

I had thought that hard links on directories were entirely impossible. What is this then? How does a folder exist in two places at once with the exact same contents?

Answer

It's a "bind mount". From the mount man page:

The bind mounts.
Since Linux 2.4.0 it is possible to remount part of the file hierarchy somewhere else. The call is

 mount --bind olddir newdir

See also http://backdrift.org/how-to-use-bind-mounts-in-linux and http://backdrift.org/how-to-use-bind-mounts-in-linux.