When you upload a video to YouTube, one of the optional fields lets you enter the place where the video was recorded. Now you can restrict YouTube's search results to videos from a certain location. Just click on the "advanced" link next to the search box, type your query, enter the location and click on "show map" to adjust your location.
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Another way to find YouTube videos recorder in a country or city is to add the YouTube mapplet to Google Maps. In some cases, you can just search for a location, select "Explore this area" and then click on "More videos" to enable the mapplet.
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