Originally Posted by
andytug
Portable devices will use GPS if you allow the relevant app to access location. If you don't they revert to the same system as the non portable ones, which is based on IP address, which is not very accurate to say the least. I'm on the Lancashire coast and anything connected to my home wifi thinks it's in Peterlee, County Durham on the opposite side of the country. This is down to multiple IPv4 NAT being used by the ISP - Network Address Translation, basically a whole bunch of sub networks in between you and the ISP, so it can't really determine your location all that well.
For some reason Google thought I was somewhere rather remote in Dumfries and Galloway for a day or so recently... perplexing as I was definitely in Sarf Lunnun and I can prove it! Normal service did resume eventually after several cache emptying exercises and a good night's sleep...