Symzonia: Voyage of Discovery
"Symzonia: Voyage of Discovery" by Captain Adam Seaborn is a work of fictional travel literature published in 1820. Captain Seaborn leads an expedition to prove the Earth is hollow, sailing to the South Pole and discovering an entrance to the planet's interior. There, his crew encounters the Symzonians—an extraordinarily virtuous, nearly translucent civilization with no weapons or disease. When the Symzonians learn of the violence and sickness plaguing the outer world, they make a fateful decision about their visitors' fate.