What is it about South Mimms? Further revelations from Strange Cults And Secret Societies Of Modern London by Elliott O’Donnell (1934):

“On All Hallows E’en certain members of the [Ghost] Circle were invited to meet, at eleven at night, in secrecy, at cross-roads not far from South Mimms. All turned up, the founder, as usual, arriving first, and on the neighbouring clock striking midnight, they were surprised to see a herd of pigs trotting down the road towards them, road and pigs gleaming white in the moonbeams. Never had any of the members of the Ghost Circle seen such pigs! They seemed to be positively gigantic, but thin. On they came, perfectly noiselessly, and on arriving at the cross-roads, they passed through a gateway into a field, leaving in their wake a current of icy air. There was something so strange and eerie about them that several members of the Ghost Circle, overcoming a certain reluctance, ran to the gate to have another look at them. The field, which afforded no cover of any kind, was very large, and it was empty, save for cattle. The pigs had inexplicably vanished.

“The members of the Circle learned subsequently that the cross-roads were known to be haunted by a herd of phantom pigs, but only on All Hallows E’en.”

I think at the end of this month the Hooting Yard Phantom Pig Spotting Club should convene at that cross-roads in South Mimms. Be there or be square, as the hepcats used to say, half a century ago, daddy-o!