Revelation 21:15-16

15The angel who talked with me had a measuring rod of gold to measure the city, its gates and its walls. 16The city was laid out like a square, as long as it was wide. He measured the city with the rod and found it to be 12,000 stadia That is, about 1,400 miles or about 2,200 kilometers in length, and as wide and high as it is long.