Project: The Greater Pyramid in William Hope Hodgson's The Night Land
The Night Land is based on the science of an earlier time, but it's science fiction. So I'm going to try to make the Pyramid as technically workable as I can.
The Great Pyramid in which humanity survives after the extinction of the Sun is not the largest construction project in human history: that has to go to the World Road the Moving Cities travelled, when Earth's rotation was slowing, in the Age When the Cities Always Moved Westward. But it's possible that it's the largest single object ever constructed in Mr. Hodgson's universe. It is, at any rate, huge.
For anyone r