A lost and hungry traveller, who was particularly known to be much better suited for travelling by sea than air, spent a good part of one long night relentlessly heading straight south for 400 miles. At which point, he began hearing strange sounds and spotted a very distant and unfamiliar flag.
Ever curious, but wanting to avoid any confrontation, he turned right to move straight west for 20 miles, then made a second right to head straight north again for another 400 miles. At which point he arrived right back where he'd began that night.
Who was the traveller? Where was he travelling? What flag did he see?
A map or regional knowledge may be required.