The Newton Stone - is an ancient pillar stone, found in Aberdeenshire, Scotland. The stone contains two inscriptions, one identified as Ogham, but the second script has never been positively identified and many different decipherments or theories have been proposed since the 1850's.
The Green Children of Banjos. In 1887, two small children were found near the town of Banjos, Spain. Their language was unknown, and it wasn't Spanish. Their skin had an odd green tint. The boy soon died, but he girl survived for about 5 years and explained that she came from a place of "perpetual twilight..." This seems to be a retelling of "The Green Children of Woolpit" from the 12th Century. Anyway, it's still a mystery!
The Kensington Runestone is a 202-pound slab of greywacke covered in runes on its face and side which, if genuine, would suggest that Scandinavian explorers reached the middle of North America in the 14th century. It was found in 1898 in the largely rural township of Solem, Douglas County, Minnesota, and named after the nearest settlement, Kensington.