The Great Ziggurat at Ur

This mighty Ziggurat, the "Mountain of God" as Ur, was erected by Ur-Engur, a king of the Third Dynasty of Ur, about 2400 BC, probably on the site of an even earlier temple. The shrine in the centre was of blue glazed brick. The Ziggurat remained in this form until it was restored by Mabonidus in the 6th century BC,

From Wonders of the Past