Jacksonville is about 5 times bigger than Las Vegas.

Las Vegas (map shows its 26 named neighbourhoods; the area covers the whole city) is approximately 367 sq km, while Jacksonville (map shows its 197 named neighbourhoods; the area covers the whole city) is approximately 1,935 sq km, making Jacksonville 427% larger than Las Vegas.
Tip: This to-scale comparison of Las Vegas vs. Jacksonville uses the Mercator projection, which distorts the size of regions near the poles.
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