THIS MIGHT SURPRISE YOU
The answer
A cube. The angel measures the city at "twelve thousand stadia; its length and width and height are equal" (Revelation 21:16). Twelve thousand stadia is about 1,500 miles each way.
Why it’s interesting
Most ancient cities had irregular walls, so even four equal sides would stand out. The wall around this one is 144 cubits, and each of its twelve gates is a single pearl (Revelation 21:17, 21:21).
Scholarly consensus
Learn the Bible.
Not just the stories, but the history, authorship, and scholarship behind it.