<p>This detail from a Japanese map depicts an area near Pyongyang, North Korea. Explore the full version <a href="https://purl.stanford.edu/bx744rr7866">here</a>.</p>

This detail from a Japanese map depicts an area near Pyongyang, North Korea. Explore the full version here.

Photograph from Stanford University

Secret Japanese Military Maps Could Open a New Window on Asia's Past

The recovered maps provided valuable intelligence for the United States after World War II.

These maps were captured in the waning days of World War II as the U.S. Army took control of Japan. American soldiers confiscated thousands of secret Japanese military maps and the plates used to print them, then shipped them to the United States for safekeeping.

The maps covered much of Asia, and they went far beyond the local topography. They included detailed notes on climate, transportation systems, and the local people. It’s the kind of information that could be used to plan an invasion or an occupation, and some of it was gathered by spies operating behind enemy lines. To the Japanese, these maps are known as gaihōzu—maps of outer lands.

To the Americans, they were a valuable source of intelligence, not

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