Transport & space · c. 3,500 BCE

The wheel

A disk on an axle turns dragging into rolling and multiplies what an animal can haul.

The earliest wheeled vehicles appear almost simultaneously around 3500 BCE across Mesopotamia, the Pontic steppe and Central Europe. The Ljubljana Marshes wheel, about 5,150 years old, is among the oldest surviving. Paired with draft oxen, the wheeled cart made overland transport of harvests and building material practical.

See it in the living treeWikipedia