Ur

Introduction
The city was believed to have existed about 5,000 years ago in what is today modern Iraq.

According to Wikipedia:

"the kings of Ur became the effective rulers of Sumer, in the first dynasty of Ur established by the king Mesannepada (or Mesanepada, Mes-Anni-Padda), who is on the king list and is named as a son of Meskalamdug on one artifact."

Lost
It is unknown why Ur was abandoned.

Found
In 1854, archaelogists discovered the remains of a building called a ziggurat. The ziggurat has since been dated to 2,100 B.C.E, during the reign of King Ur-Nammu. They believed the ziggurat was designed to represent a mountain reaching up to the gods; particularly, the moon god Nanna.

Ur was fully excavated in 1920s by British archeologist Leonard Woolley. In the burial chambers, he found the remains of animals pulling wheeled vechicles, and skeleton remains of men and women, including their decorated headdresses and clothes.