A small one. This is the Sites page of a board for a data centre demo called DC Ashvale, with the window on Realtime · Last 24h.

The Sites table has one row: DC Ashvale, Warning, 7 devices, 4 open alarms, last seen now. The map shows the site as an orange marker, and the legend counts sites per status (Critical 0, Warning 1, OK 0, Unknown 0). Under the table is a card that counts devices that have a place but no site and points to Sites & Assets. It says 0, which is what you want.
Four open alarms and still only Warning: an open alarm raises a site to at least Warning, and only a critical alarm or a device reporting a critical status makes it Critical. How the status is worked out is on Site status and the status key.