404 not found error

After copying drupal content to the httpdocs  the site was behaving not as needed so got rid of the drupal content and with the initial set of file was getting "404 not found error"
The requested URL / was not found on this server.

referring the /var/log/apache2/error.log showed
[mon Mar 01...][error][client 192.168.1.2] file does not exist: /var/www/gnumen.net

after having a look in /etc/apache2/site-available