An army of keyboard warriors cannot be infiltrated if there is no command and control. This, however, requires each individual to be completely self-motivated, self-directed, and self-resourced.
I don't know what a museum to the anons might look like, but if it has an extremely long and arduous walk from the parking lot then that should help to convey the right aesthetic.
And no door to get in...Just a series of rabbit holes and you have to discern whether or not you really got in or are somewhere else?? Maybe a parallel universe where the Nazis won WWII...Oh wait that already happened...Never mind you get my drift...If you know you know ;)