In 1832, a human skeleton was unearthed in a sandbank in Fall River, Mass. A triangular plate of brass covered its sternum, and it wore a broad belt of brass tubes. The grave also contained a number of brass and copper arrowheads. To judge from the skull, the skeleton had belonged to a young man, but from where? The local Indian tribes did not work brass.

One commentator claimed it as evidence that the Phoenicians, Carthaginians, or Egyptians had discovered North America in the remote past. Later historians speculated that an early Norse explorer might have traveled south from Newfoundland, but the style of armor was unknown to medieval Norway. A third possibility is that it belonged to an early European colonist, perhaps a Portuguese explorer.

The skeleton was destroyed in a fire in 1843, so there’s no way now to date the remains scientifically, or to gather any further information. Its identity must remain a mystery.

The following remarkable account of the stoppage of Niagara Falls, appeared in the Niagara Mail at the time of the occurrence: “That mysterious personage, the oldest inhabitant, has no recollection of so singular an occurrence as took place at the Falls on the 30th of March, 1847. The ‘six hundred and twenty thousand tons of water each minute’ nearly ceased to flow, and dwindled away into the appearance of a mere milldam. The rapids above the falls disappeared, leaving scarcely enough on the American side to turn a grindstone. Ladies and gentlemen rode in carriages one-third of the way across the river towards the Canada shore, over solid rock as smooth as a kitchen floor. The Iris says: ‘Table Rock, with some two hundred yards more, was left dry; islands and places where the foot of man never dared to tread have been visited, flags placed upon come, and mementoes brought away. This unexpected event is attempted to be accounted for by an accumulation of ice at the lower extremity of Fort Erie, which formed a sort of dam between Fort Erie and Buffalo.'”

— Barkham Burroughs’ Encyclopaedia of Astounding Facts and Useful Information, 1889

The magnificently named Lake Winnipesaukee Mystery Stone is just that — an odd carven stone, about 4 inches long, turned up by workmen digging a fence post in New Hampshire in 1872.

No one knows who carved it, when, or why. On one side are carved an ear of corn, a deer’s leg, and several other figures. One the other side are inverted arrows, a moon shape, a spiral, and some dots.

When the stone first came to light, the American Naturalist suggested that it “commemorates a treaty between two tribes.” But after an analysis in 1994, state archaeologist Richard Boisvert said that the holes drilled in the top and bottom are more consistent with power tools from the 19th or 20th century. He said that scratches in the lower hole suggest that the stone was placed on a metal shaft and removed several times. We’ll never know its real origin.