It was a running gag that on the official town plaque the last listed sister city was Gehenna, A.K.A Hell.
As town historian I looked into it. Turns out in late 1600’s, height of the witch hysteria, the then mayor ‘made a deal’ so that all witches would leave the town alone.
The town council found this hilarious, and so a Sister City celebration was organised for Halloween week. Lots of events, witch pageants, keys to the city given to people in silly devil costumes, lots of kitschy touristy crap.
Actually went pretty well.
What, you expected something else?