[Taltarzac725]

How the Great Wall of China Was Built — Materials, Methods

Looked this up in case it gave some hints at how they could also have built the pyramids.

[ColdNoMore]

As a side note, it is an urban myth...that it can be seen with the naked eye from outer space.

[Jima64]

Lots and lots of slaves.

[Arctic Fox]

Originally Posted by ColdNoMore

As a side note, it is an urban myth...that it can be seen with the naked eye from outer space.

There is only one man-made object that can be seen from the International Space Station

[Taltarzac725]

Originally Posted by Arctic Fox

There is only one man-made object that can be seen from the International Space Station

The Greenhouses of Almeria | Amusing Planet

Probably this but it looks like many greenhouses in one spot.

[Arctic Fox]

Originally Posted by Arctic Fox

There is only one man-made object that can be seen from the International Space Station

and that is (drumroll, please): the International Space Station