Revelation 21:14-16

Revelation 21:14-16. And the wall of the city had twelve foundations, and in them the names of the twelve apostles of the Lamb. And he that talked with me had a golden reed to measure the city, and the gates thereof, and the wall thereof. And the city lieth foursquare, and the length is as large as the breadth: and he measured the city with the reed, twelve thousand furlongs. The length and the breadth and the height of it are equal.

This is an idea scarcely to be grasped, to see a city which is as high as it is broad. Such cities cannot exist on earth. They are meant for that glorious future state. They will exist under the new heavens and in the new earth, for which we look at the coming of our Lord.