All emails that match the criteria for quarantine will be sent here so that the admins and super admins can classify and choose the appropriate action. It's recommended to adjust the safety settings so that all suspicious email is sent here:
All newly quarantined messages will land in the All Quarantines tab. Super admins can create sub-categories for better manual classification using Manage quarantines.
If you are using Chrome, you can create app-like direct access for this (or any other) part of the G Suite admin console by clicking in the top-right corner of the browser, and then More tools, followed by Create shortcut ...