In Bavaria from medieval through early modern times, magic was regularly used in an attempt to induce wolf attacks on people (and to counter such magic, too).
A construction worker, when his boss innovated and put a rubber tire on the wheelburrow, said it was the best thing for the worker since the paycheck.
The Tower of Hercules, built in Spain during the Roman Empire, is the oldest operational lighthouse in the world. Second place to the medieval Irish Hook Lighthouse, which was a monastery of monks appointed to light the beacon fire.
Nineteenth century writers on elementals -- sylphs, undines, salamanders, gnomes -- frequently compared them to such things as X-rays, radioactivity, or radio waves.
The consular year began on January 1st in ancient Rome, because it was accelerated once to get a consul in office and out to help in the Second Celtiberian War. (They still suffered a defeat in August so crushing that the day was declared a dies ater and regarded as so unlucky that no Roman general would willingly fight on it.)
Hoover Dam was the first hard-hat construction; one of the bosses introduced them because of all the problems with falling rock.
Gotland is the place to go if you want buried pirate treasure. The Vikings brought back treasure, and would bury it for safe-keeping. It appears that an inexplicably large percentage was so safe its owners never found it again.
During the Revolutionary War, Cornwallis wrote, "We may destroy all the men in America, and we shall still have all we can do to defeat the women."
Welsh informants told 19th century folklorists that the fairies couldn't stand Methodist preachers or teetotalers.
Shinto temples are carefully demarked by boundaries. Even of rope or paper, they contain the holy ground within to prevent its contamination. And if it should be corrupted and become unholy, the boundaries will keep it in.
Great Britain sent an original copy of the Magna Carta to the New York World Fair -- in 1939. In 1940, after some discussion, it was agreed that it would remain in the United States for safekeeping. It went back only in 1947.
The Flamen Dialis of ancient Rome had a long list of forbidden actions. Such as sleeping for three nights outside his own bed, mounting a horse, looking at a legion under arms, swearing an oath, wearing most jewelry, eating leavened bread, and touching a dead body.
In the 19th century, steamers would not issue return tickets for trips to West Africa.
Francis I of France issued a law that victorious duelists had to pay compensation to the dead man's family and for the funeral.
The fervent denunciation of American munition makers as the instigators of WWI -- even the government had rebuked them, in the Nye Commission -- had effects. Businesses pulled away from the work. It did not help WWII rearmament.
Christmas Eve is the Italian Festival of Seven Fishes, which is to say, the dishes for dinner need to be made from seven fishes. (It's still in the fast of Advent, but it is, after all, Christmas Eve.)
The Knights of Ålleberg, in Sweden, are a classic form of the legend of the king in the mountain, who will return in his (their) country's hour of need. Variants differ about whether there are twelve or thousands -- though in this case, folklore helpfully supplies that it began with twelve, but other knights have joined them.
A 19th century British account of a woman returned by the Good Folk after seven years said she had no toes, she had danced them off at their dances.