District of Columbia is about 563 times smaller than South Korea.

South Korea is approximately 99,720 sq km, while District of Columbia is approximately 177 sq km, making District of Columbia 0.18% the size of South Korea. Meanwhile, the population of South Korea is ~51.8 million people (51.2 million fewer people live in District of Columbia).
Tip: This to-scale comparison of South Korea vs. District of Columbia uses the Mercator projection, which distorts the size of regions near the poles.
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