Looking for logging into the Salesforce Admin site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Salesforce Admin site. After that you can login as usual with your login credentials.
https://login.salesforce.com/
https://help.salesforce.com/apex/HTViewSolution?urlname=Enabling-Organization-Admins-Can-Login-as-Any-User
https://admin.salesforce.com/
https://help.salesforce.com/apex/HTViewHelpDoc?id=logging_in_as_another_user.htm&language=en
https://trailhead.salesforce.com/career-path/admin
https://help.salesforce.com/HTViewHelpDoc?id=granting_login_access.htm
https://trailhead.salesforce.com/credentials/administratoroverview
https://success.salesforce.com/answers?id=90630000000ZewTAAS
https://trailhead.salesforce.com/credentials/administrator
https://www.webassessor.com/wa.do?page=publicHome&branding=SALESFORCE
https://www.adminhero.com/lightning-login/
https://www.cio.com/article/2685352/customer-relationship-management/salesforce-administrator-responsibilities.html
https://webkul.com/blog/grant-login-access-salesforce/