Russia
I'm not sure about my answer, but I think Gustave Eiffel has built the most buildings in the world.
Diamonds lost during World War II were lost. This means that there are no records available to use to answer your query, sorry.
Indiannapolis
the Allied Powers
Serbia
The Soviet Union :)
Russia, with over 3.3 million deaths.
Avoid tall buildings.
Most subs that were lost we're on Germany's side because they employes the most subs, and after the code was broken subs began sinking on the German side routinely.
Millions of buildings were destroyed during World War 2. Most of these were resulted of being knock down by Air Assults or tanks firing or mis firing at buildings e.g. Stalingrads buildings were mostly destroyed during the course of world war 2.
If mausoleum, then Taj Mahal, if house, then FallingWaters