GPS – how odd!
Tracking my activity (walk) into the village, my iPhone’s GPS put me in some odd locations.
The red block is where I shopped in Waitrose – I never went to the left as would be suggested by GPS. The red circle is where I stopped to make a longish phone call.
All very odd, though perhaps explained by the accuracy of GPS, the strength of the GPS signal and the quality of my iPhone’s GPS receiver,

Update: I came across the following at Why-is-GPS-data-sometimes-inaccurate
When signals from the GPS satellites bounce off buildings, the GPS receiver can be confused by the extra time the signal took to reach it. In these cases, you may observe sudden large errors in position. There is not much that can be done to reduce the effects of multipath errors – GPS is simply less accurate in canyons, whether they are made of buildings or natural formations.