Rosetta Stone

The ‘Rosetta Stone' is a dark granite stone (often incorrectly identified as "basalt") which provided modern researchers with translations of ancient text in Egyptian demotic script, Greek, and Egyptian hieroglyphicss. Because Greek was well known, the stone was the key to deciphering the hieroglyphs in 1822 by Jean-François Champollion, and in 1823 by Thomas Young. The discovery facilitated translation of other hieroglyphic texts.

The stone has been kept in the British Museum since 1802

Also see other discoveries

Amesbury Archer
Dead Sea Scrolls
Java Man
Kennewick Man
Lindow Man
Linear B
Narmer Palette
Neandertal
Ötzi
Peking Man
Red Lady of Paviland
Sweet Track
Tollund man
Turkana Boy