I’ve been trying to solve this problem pretty much since Aperture 3 came out with it’s Places/GPS support. Every time I added location information to a photo, it wound up being tagged as where I really took the photo but also a completely incorrect, but consistent location (for me it was always The House of Binns in Scotland). Location information pops up in so many different places in Aperture and displayed in so many different ways that it was really hard to track down what was going on – sometimes it would have the first part of the place name right, but then had the country incorrectly shown as Scotland.

Today I finally worked out what was happening. The key thing to understand is that your photos aren’t tagged with a place name, the photo metadata only includes GPS coordinates. Aperture then maintains a separate database of place names which includes the name, the GPS coordinate at the center and the size of the place (as a radius). So a place record for your home address would have a very small radius, but you could just as easily create a place for an entire country with a big radius. When Aperture wants to display location information, it simply finds a list of all the places it knows about whose location and radius includes the photo’s GPS coordinates. As such, a photo might be in any number of “places”.

So the reason the photos are being incorrectly labelled, is that somehow a place was created called “The House of Binns” with it’s central location at The House of Binns in Scotland, but it’s radius roughly big enough to include most of Europe. So any photo taken anywhere in the UK or half of Europe was within the range of this place called “The House of Binns”.

To view the places that you’ve defined, simply go to the “Metadata” menu and choose “Manage My Places…”. You’ll get a dialog very much like the one for Assign Location but when you click on a place name in the left column a little minus icon appears. Simply click that icon to remove the place from your database, or adjust the location and radius on the map. Deleting places in this dialog won’t remove the GPS coordinates from your photos – only the particular name mapping you’ve added.