No records exist to explain Easter Island’s monolithic statues, the moai.

These enigmatic documents have kept their secrets for centuries

From the Voynich Manuscript to the tablets of Easter Island, the craftiest cryptologists haven't decoded these mysteries of history.

No records exist to explain Easter Island’s monolithic statues, the moai.
Photograph by Kent Kobersteen/National Geographic Image Collection

One would think an ancient object covered in text—or symbols—would be an archaeologist’s dream. What better way to learn about the past than from the direct words of the ancients? The groundbreaking discovery of the Rosetta Stone in 1799 and its decoding in 1822, for example, unlocked the intricate details of Egyptian hieroglyphic writing. 

But sometimes, archaeologists come across ancient texts that, as exciting as they may be, refuse to give up their secrets. Here are some, including a symbol-stamped clay disk, the Easter Island tablets, and a 16th-century world map depicting landmasses allegedly unknown at the time it was charted, that still grip onto their ancient mysteries. What secrets are they holding?

The Minoan kingdom flourished on the Greek island of Crete between 3000 B.C. and 1100 B.C. One of the earliest urban societies, they built elaborate palaces and used sophisticated plumbing, heating, and sewage systems. They also may have left behind a mysterious six-inch, fired-clay disk, which Italian archaeologist Luigi Pernier discovered in 1908 in the ruins of the ancient palace of Phaistos. Dating from perhaps 1700 B.C., this amazing find bears a spiral of 242 stamped symbols. Many have recognizable shapes, such as a tattooed head, an arrow, a plane tree, a cat, and a beehive. They may represent phonetic groups or syllables, but there are too few of them to be deciphered. No other artifact has ever been found with the same symbols. Attempts to unravel its mystery—Cretan? Foreign? Syllabic reading inward? Alphabetic reading outward?—are as varied as its interpreters. The fact that symbols are stamped may suggest a capacity for mass production, although no other discovery supports that.

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