Both Mayans and Egyptians came up with the idea of constructing pyramids as part of their cultural identity.
You have been living your whole life on a planet. Planets make up solar systems, solar systems make up galaxies, and galaxies make up universes which make up all of existence in space.
I think that the best answer to this is foreign investment: it was the one aspect which has helped Bulgarian economy the most.
The foreign investment is mostly connected to tourism - especially for example when rich western Europeans buy property in Bulgaria for private use.