Could ancient humans really have built the pyramids without extraterrestrial help? Or do such questions reveal more about modern anxieties than the past itself?
EL MUNDO on MSN
Francesco Sauro's journey to the center of the Earth: "You see things that are not in your head and have very strange dreams"
The speleologist and astronaut trainer publishes 'The Dark Continent,' a journey through the secrets beneath our feet: "We ...
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