colonization of Earth theme

A permanent alien settlement is established on the planet Earth.

Examples

A well-known archaeologist discovered the site of a hundreds of thousands of years old Martian colony deep inside Africa in "The Retreat to Mars" (1926).

2 total · 1 major · 1 minor

StoryLevelMotivation
movie: Man from Atlantis II: The Death Scouts (1977) major The two waterbourne aliens came to scout Earth's ocean's as a possible target for colonization.
shortstory: The Retreat to Mars (1927) minor Hargraves was shocked to discover that Martians had colonized the Earth some hundreds of thousands of years ago.