Watch Nazi Mega Weapons

In 1934 the Japanese begin designing The Yamato, the most powerful battleship in history. Japan is determined to retain control in the Pacific so builds a ship 30 percent larger than anything their enemies have. Constructed in absolute secrecy, the Japanese go to extraordinary lengths to ensure no detail is revealed.

In June 1940, the Nazis set foot on British soil. The Channel Islands, a British territory since the 11th century, is now under German rule. Hitler becomes obsessed with holding onto this small corner of Britain and demands the construct of a network of extraordinary fortifications across the island. In his bid to hold on to the territory, the islands become one of the most heavily fortified pieces of land in the whole of Europe.

Once Hitler seizes power in 1933 he transforms his Alpine retreat in the sleepy district of Obersalzberg in Bavaria into a vast mansion called the Berghof. The area becomes a magnet for the most powerful Nazis and Hitler's Berghof a show piece for the Reich. Aided by his most trusted assistant Martin Bormann, Obersalzberg is quickly transformed into Hitler's own fortified fiefdom.

The tide of war in the Pacific has now fully turned against the Imperial Japanese forces. In a fierce and brutal island hopping campaign, the Americans are winning battle after battle, rapidly gaining ground in their ultimate goal of invading mainland Japan. However, the Japanese decide that the island of Okinawa will be their last bastion of defense. It is a key strategic location for the Americans, but as Japanese territory, the Japanese will defend it at all costs.

By early 1943 Nazi Germany is losing the battle in the Atlantic. Their U-Boat menace is no longer invulnerable to attack; it could cost them the war. But Hitler and Kriegsmarine High Command are one step ahead. Since 1940, they've been planning a submarine capable of fast underwater speeds and phenomenal firepower that will outperform anything that has gone before. Designated the Type 21, it's the world's most advanced submarine: Hitler's sea-faring super weapon.

In the first years of World War II, Hitler's Germany crushes its enemies in a series of lightning offensives. A new word is coined to describe this incredible string of successes: "Blitzkrieg" or "Lightning War." Extraordinary ruins scattered across Europe tell the story of a revolution in tactics and weapons which almost gives Hitler the chance to create his Thousand Year Reich.