Architecture began the first time humans built anything to live in. A lean-to, wickiup or grass hut is architecture.
Primitive mankind left us evidence in circles of stones meant to weigh down the edges of skin tents. Early Native Americans built mounds and towns with buildings of various materials as far back as 5000 BC. Cities built of brick and stone in the Middle East began about the same era, Akkad possibly the first, followed by cities such as Babel, Calneh, Gawra, Asmar, Fara, Lagash, Ur, Ninevah and Erech.
Stonehenge, originally a wooden structure, was rebuilt in stone around 3000 BC. The first pyramid in Egypt, a step pyramid, was built about 2789 BC by Imhotep, architect of Pharoah Djoser (or Zoser). The smooth-sided pyramid appeared in the Fourth Dynasty under Pharoah Snefru in the 26th century BC. The Great Wall of China was begun around 25 BC, and in the 1st century BC the Roman architect Marcus Vitruvius Pollio wrote De Architectura, the first classic work on the art of architecture.