If you have a website with a url like this: www.example.com then you can find the robots.txt by adding this: www.example.com/robots.txt
Then if you see something like this:
User-agent: *
Allow: /
Disallow: /inbox/
Disallow: /levels/
Disallow: /levels/extras/userpass.txt
Disallow: /users/
User-agent: Mediapartners-Google
Disallow:
#Begin Attracta SEO Tools Sitemap. Do not remove
sitemap: http://cdn.attracta.com/sitemap/2165581.xml.gz
#End Attracta SEO Tools Sitemap. Do not remove
Then you see the sitemap. Robots directory is inside every website and can have useful information to administrator access, but you wont always find the sitemap.