Spinning Compass Network

I have considered a few facts, namely that my dear wife is not here to organise my calendar, there is not a great deal to do here beyond seeing to my nephew's education, and it seems an altogether upside-down place anyway. As a result I should like to announce that young Sirius and I will be at home to visitors every Wednesday.

Has anyone with magical knowledge investigated these doorways that seem to appear here, and tried to chart and predict them? I do recall a rather misadventurous outing to France when I was a boy, but I am told they are at least partly regular. I wonder if they are marked by any magical disturbance.