Hitler's secret Nazi war machines of World War II

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Heinrich Himmler, head of Hitler's Gestapo and the Waffen-SS, stands next to Adolf Hitler.

Nearly 83 years ago this month, Hitler secretly began rearming the Nazis despite violating the Versailles Treaty.

In 1934, Hitler told Nazi military leaders that 1942 was the target year for going to war in the east.

Hitler's engineers secretly developed some of the most ambitious projects and rapidly produced sophisticated technology decades before its time.

In the 2015 fall issue of Weapons of WWII magazine, author KM Lee detailed some of Hitler's advanced weaponry.

Here's a look at are some of the secret, lethal weapons the Nazis created during World War II: