Revelation 21:15-17

The angel who talked with me had a measuring rod made of gold to measure the city, its gates, and its wall. The city was built in a square, and its length was equal to its width. The angel measured the city with the rod. The city was 1,500 miles long, 1,500 miles wide, and 1,500 miles high. The angel also measured the wall. It was 216 feet high, by human measurements, which the angel was using.