We planned to use our long layover to explore a new city. It completely backfired, but we'd try it again.

I didn't realize I'd need a visa to leave the airport in Istanbul during my layover.

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• As an American, I didn't realize I needed a visa to leave Istanbul's airport during my long layover.
• The oversight cost me more time, money, and stress than anticipated.
• Now I know that researching country-specific entry and visa rules can prevent costly mistakes.

My fiancé and I have a knack for piecing together budget-friendly flights, and last August...