Christmas type holiday that can be thrown into any city/town.
The addition of “irrelevant” details adds local colour to a campaign world, giving the impression that the DM has thought very deeply about the history of even the smallest architectural feature.
Small village tavern specialty of the house is fresh cow blood mixed with milk. For each order they go out back and actually draw blood from a cow by puncturing a vein in it's neck. Fresh blood brought to the table where they poor milk into the glass of blood in front of the customer so they know how much blood they are getting.