ADR already has buildings called "Collection Facilities", where they keep anomalies that are in some way disrupting the peace, so that they can study them and stuff. For example, idk, you can say "ADF-XX is currently being kept in Collection Facility #16 due to its extreme violent nature." It should be noted that not all anomalies need to be collected. ADR is not trying to hide all anomalies from the public; it just keeps things peaceful. The facilities are also used for keeping donated anomalous objects and trinkets, and other bullshit.
Those are ADR's versions of "Sites" currently, but eventually, we would love to have writers write stories on what goes on in those facilities, and other secret ADR physical components, so that readers can get a better picture of the whole ADR thing.
And yeah, as the wiki slowly grows, there will definitely be a page about all of the departments, their lore, random stories, etc., told from the perspective of ADR's anonymous employees.