I'm wondering if there is a way to prevent people from viewing the "concrete" directory on your site?

For example, if you installed concrete to the root of your website, they could type:
"www.yoursite.com/concrete"

and get a listing of the files there.

It appears that anything that really matters is protected from access, but I'm wondering if there is a way to prevent people from seeing it entirely?

As a side note, I've changed the name of this directory but the name could still be determined by viewing the source code. Thanks!