@Boney would it be possible to create a Runic/magical/hybrid runic-magical room in a tower that's dedicated entirely towards protecting the interior from external foreign mental influences? Essentially an equivalent of an inverted containment unit like Unit 3125 from
CASE COLOURLESS GREEN(spoilers if you haven't read There Is No Antimemetics Division, you should really read the previous three entries in the series before CASE COLOURLESS GREEN). Boring case scenario we find nothing, best case scenario we find glimpses of evidence of Ulgu Dragons we previously couldn't perceive but now can pass on written instructions to our outside self to gather more information about them and hopefully break their veil without the need for a shielded room, bad case scenario we discover a bunch of hostile antimemetic entities we have to deal with which we'll forget the moment we leave the room and the only way to deal with them is to leave written notes to our amnesiac self on how to handle them and hope that's enough, worst case scenario
we discover a virulent contagious antimemetic cognito/info/memetic hazard analogous to SCP-3125 for whom the only way to contain its spread once discovered is to either stay in the containment unit until you die or find a way to give yourself amnesia before you exit and the only way to truly stop it would be to devise some sort of countermeasure either in the original inverted containment unit or find a way to build another inverted containment unit dedicated to building the countermeasure with the necessary size and resources without letting it slip to anyone why you might be diverting resources towards building such a thing and as such just in case the worst case scenario does come to pass measures should be taken to supply the interior of inverted containment units with plenty of alcohol, amnesia-inducing drugs and magic like mindhole, and easy ways of inducing head trauma and associated amnesia, as well as a precommitment strategy for any that enter to precommit themselves to obeying any written instructions originating from inside the inverted containment unit no matter their contents.
Anyway now that the details of the various possible scenarios of what we might discover and how we should respond have been eclidated,
@Boney is the basic concept sound, a room that via runic, magical, or hybrid means excludes foreign mental influences from reaching its interior?