This section of a mosaic floor comes from a bedroom in the House of the Centenary, one of the largest houses in Pompeii. The house was built in the fifth century B.C., the Samnite Period, before the Roman colonization of Pompeii, and was renovated almost continuously from the second century B.C. until 79 A.D.

The mosaic is made primarily of black and white tesserae, the small marble pieces that are laid in a pattern when the floor is constructed. The center emblem, which is made of colored tesserae, depicts a gorgon. Medusa, the most famous of the gorgons, was a mythological creature with snakes for hair and whose eyes could turn the beholder to stone.