This relief appears on an 18th-century monument on the grounds of Shugborough Hall, a country estate in Staffordshire, England. The shepherds are pointing to this inscription:

    O•U•O•S•V•A•V•V
D•                   M•

What does it mean? No one knows. If it’s a ciphertext, no one’s been able to solve it, and that includes the codebreakers at Bletchley Park, who cracked the German Enigma code in World War II.

If you can decipher it, there may be a reward in it for you: Some say the message contains a clue to the location of the Holy Grail.

In the early morning hours of Feb. 25, 1942, someone reported a mysterious object flying over Southern California, and L.A. briefly went nuts. A blackout was ordered, sirens were sounded, and the military fired more than 1,400 anti-aircraft shells into the night sky. Some said they struck the object; certainly they struck several buildings, and killed three civilians.

No one knows what really happened that night. The object could have been a weather balloon, a blimp, a Japanese fire balloon, or nothing at all. Navy secretary Frank Knox chalked the whole episode up to war nerves. With three local residents dead of heart attacks, that seems as good an explanation as any.

In 1821, a shoemaker in the south side of Edinburgh, while engaged in cleaning a cage in which he kept a lark, left the door of the cage open, of which the bird took advantage, and flew away by a window at which its owner was then standing. The lark being a favourite, its loss was much lamented. But it may be imagined what was the surprise of the house, when about an hour after, a cat, belonging to the same person, made its appearance with the lark in its mouth, which it held by the wings over the back, in such a manner that the bird had not received the least injury. The cat, after dropping it on the floor, looked up to those who were observing her, and mewed, as if to attract attention to the capture. The lark now occupies its wiry prison, with the same noisy cheerfulness as before its singular adventure.

— The Cabinet of Curiosities, 1824

In August, 1823, a man undertook to carry thirteen sieve-baskets, piled one upon another on his head, from Dean-street, Westminster, to Perry’s potato-warehouse in Covent Garden. The wager was for a sovereign; and the conditions were, that he was to walk through the public streets, and to arrive at the place named with eleven on his head, without resting. He walked with great caution, sometimes in the carriage road, and sometimes on the pavement, followed by numbers of people, who, however, at once encircled and cleared the way for him. His greatest difficulty seemed to be to avoid the lamp irons when upon the pavement, as the upper sieve, which poised the whole, had a continual inclination to the right side. He succeeded in gaining the middle of Southampton-street without losing one sieve, having passed coaches and carts of all descriptions; when here, the upper sieve fell to the ground. He halted for a moment, and poised the remaining sieves, with which he proceeded full into the market, where he cast the whole down, amid the cheers of the populace. Though the weight must have been considerable, the poising the sieves was the greatest difficulty he had to encounter, as they reached the second floor windows. He won his wager; and many gentlemen, who were highly delighted with the novelty of the scene, subscribed to reward his ingenuity and perseverance.

— The Cabinet of Curiosities, 1824

At Bristol I saw a shaved monkey shown for a fairy, and a shaved bear, in a check waistcoat and trowsers, sitting in a great chair as an Ethiopian savage. This was the most cruel fraud I ever saw. The unnatural position of the beast, and the damnable brutality of the woman-keeper who sat upon his knee, put her arm round his neck, called him husband and sweet-heart, and kissed him, made it the most disgusting spectacle I ever witnessed.

— Robert Southey, Southey’s Common-Place Book, 1851

In 1931, farmer Michael Trent shot two strange creatures in the Aberdare Mountains of central Kenya. They appeared to be small lions, but they bore spots.

Were they a natural hybrid of leopard and lion? A new species? A subsequent expedition found nothing, and no one’s seen one since.