More like Underground Kingdom

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Allan QuatermainSeries
series25 books1885
Set in africa and 19th century.
“An English professional big game hunter and adventurer, in film and television he has been portrayed by Richard Chamberlain, Sean Connery, Cedric Hardwicke, Patrick Swayze and Stewart Granger among others.”
from the catalogue
Start with Marie →
The Cave GirlNovel
Edgar Rice Burroughsstandalone novel1925
Set in lost world and our world.
The People of the MistNovel
H. Rider Haggardstandalone novel1894
Set in lost world and 19th century.
Tolkien's legendariumUniverse
universe163 books1923
Set in secondary world.
“Before the seas were bent and the mountains raised, there was Music — and from that Music came Arda, and in the west of Middle-earth the long defeat and stubborn hope of those who dwell there.”
from the catalogue
Start with The Fellowship of the Ring →
includes The Hobbit, The Lord of the Rings, The History of Middle Earth, The Fall of Gondolin, The History of the Lord of the Rings
TarzanUniverse
universe100 books1912
Set in early 20th century.
“Deep in a jungle no map has tamed, an English lord's orphaned son is suckled by a she-ape and grows to manhood knowing neither his name nor his kind.”
from the catalogue
Start with Tarzan of the Apes →
includes Tarzan, The Tarzan Trilogy, The Wild Adventures of Tarzan, Tarzan's Africa / Opar / Khokarsa, Tarzan and the Martian Legion
Edgar Rice Burroughs' Pellucidar universeSeries
series24 books1922
Set in lost world.
Start with At the Earth's Core →