Revelation 21:15-16

15The angel who talked to me had a long gold stick. He used it to measure things. So he could measure the city and its gates and its walls.

16The shape of the city was a square. It was as long as it was wide. The angel measured the city with his stick. It was 12,000 stadia (2,400 kilometres) long. It was as wide and as high as it was long.