Hollow Earth

Halley proposed it; Byrd's diary allegedly confirmed it. The openings are at the poles.

Edmond Halley proposed concentric inner spheres in 1692 to explain compass anomalies — the theory's pedigree is Royal Society, not tabloid. Symmes petitioned Congress for a polar expedition; Byrd's alleged diary describes green valleys past the pole. Seismology settled it long ago: the earth rings solid. The lore's answer is that seismology is measuring the shell, and the openings are exactly where the satellite imagery is always, curiously, composited.