There are rumors that suggest Japan maintained 2 submarine bases on Mexico’s Pacific coast during World War II...
...1 called La Palma and located in the state of Chiapas, and 1 on the Baja Peninsula at Magdalena Bay.
Spies reportedly uncovered the hidden depots “hewed out of the side of the jungle” following tips from local Yaqui Indians.
Newspaper reports in 1941 also suggest the Chiapas government discovered a Nazi radio station and airfield in the mountains.
Both the German and Japanese navies are thought to have approached Mexico in 1912 to purchase Pacific harbors in the area.
A controversial theory suggests the secret Mexican bases were intended to be a staging area for an attack on the Panama Canal.
During the Cold War, the US Army launched Project Iceworm at Camp Century underneath the Greenland ice sheet...
...a top-secret program to a build medium-range nuclear missile base that could strike the Soviet Union.
Massive trenches and tunnels, the largest of which was 1,100-ft (335 m) long, and 26-ft (8 m) by 26-ft (8 m) were dug into the ice...
...and prefabricated buildings were buried to house 200 soldiers, 600 missiles, and a nuclear power plant that powered the base.
Project Iceworm was canceled in 1966 after shifting ice crushed the base, but its existence did not become known until 1995.
It was not until 1977 that a secret Nazi weather station was uncovered at the northern tip of Canada’s Labrador Peninsula.
“Weather Station Kurt” was delivered to North America in 1943 by meteorologist Dr. Kurt Sommermeyer aboard the U-boat U-537.
Meteorological data was broadcast from the clandestine site every 3 hours over a 2-minute transmission on 3940 kHz.
To conceal the station, the equipment was labeled "Canadian Meteor Service" and empty American cigarette packs were left behind.
The operation is the only confirmed armed military operation to land on the North American continent.
In 1942, Japanese forces seized Kiska island in the Aleutian Islands, then a part of the US territory of Alaska...
...but it took nearly a year for the US Navy to respond with an invasion force after a prolonged bombing campaign and blockade.
Allied soldiers landed without resistance following a secret Japanese evacuation of over 5,000 personnel under a heavy fog...
...and they were shocked to discover that the Japanese had built an entire submarine and resupply base in the future US state.
Hundreds of roads, cars, buildings, and defensive fortifications were found abandoned and covered in graffiti.
The soldiers stationed on Lake Michigan during World War II were to tell no one of their activities...
...as they participated in a secret US Navy program floating in the middle of the US’s largest body of fresh water.
“Hiding in plain sight” were the USS Sable and USS Wolverine, two aircraft carriers used for training and experimental tests.
Both were converted Great Lakes paddle boats that lacked hanger bays and required a strong wind to launch their aircraft.
It is estimated that 100 planes and 12 pilots rest on the bottom of the lake because of their dangerously short decks.
Little acknowledgment was made as the Navy was also simultaneously testing secret drone airplanes to combat Japan’s kamikazes.