During the Cold War, Western and Eastern countries

[Bassim]

I am wondering if my sentences are grammatically correct.

During the Cold War, Western and Eastern countries spent enormous amounts of money building secret nuclear bunkers, believing they would protect the political elites from the nuclear explosions. Nowadays, many of those buildings are abandoned, but some have become museums, galleries or turned into mushroom growing farms.

 

[Charlie Bernstein]

They are.

People who like using the so-called Oxford comma would put a comma after "galleries."

And some people would hyphenate "mushroom-growing," since it's combining two words to make one adjective.

 

[GoesStation]

The bunkers were thought to protect against nuclear explosions in general. Don't use an article.

"Growing" is superfluous. Just write mushroom farms.

It's more natural to write Eastern and Western.​ I don't know why, but the opposite looks odd.