The Nebra Sky Disk, attributed to a site near Nebra, Saxony-Anhalt, Germany, is a bronze disk about 30 cm in diameter, with a blue-green patina inlaid with gold symbols which have generally been interpreted as a sun or full moon, a lunar crescent, and stars, including a cluster interpreted as the Pleiades. The disk is associated with Bronze Age Unetice Culture.
"Two golden arcs along the sides, making the angle between the solstices, were added later. A final addition was another arc at the bottom surrounded with multiple strokes (of uncertain meaning, variously interpreted as a Solar Barge with numerous oars, as the Milky Way or as a rainbow)" (Wikipedia article on Nebra sky disk, accessed 11-04-2010).
When it appeared on the antiquities market in 2001 the disk was widely suspected to be a forgery. Scientific research summarized in the Wikipedia article provided evidence for its authenticity that was widely accepted in 2010.