We journalists. . . are also extremely impressed with scientists, and we will, frankly, print just about any wacky thing they tell us, especially if it involves outer space.
No doubt Carter would describe the underground city in excruciating detail, with exact measurements of each room, boring history on every statue and hieroglyph, and background notes on the construction of the magical headquarters of the House of Life. I will spare you that pain. It's big. It's full of magic. It's underground. There. Sorted.