How do I open the Joomla Control Panel?To login to Joomla! 3 and access your administrative panel, you need to open your browser and navigate to  http://mydomain.com/administrator . On this page, you will find a login screen, where you need to enter the username and password you've chosen during the Joomla!of course there are case that the backend is in a URL like …./administrator? and with password

see also

AdminExile is a Joomla system plugin designed to secure access to the /administrator URL and prevent unauthorized access to the /administrator login form itself.