Hi Flafox,
Thanks for contacting Apple Support Communities!
We understand that you're seeing a location on your Map app that you've never been.
Although we're unable to speculate how this has happened, you can check that your Map settings and Location Services are active to ensure that Maps reports your location properly as outlined here: View maps on iPhone - Apple Support
"Allow Maps to use your precise location
To find your location and provide accurate directions, iPhone must be connected to the internet, and Precise Location must be on.
- If Maps displays a message that Location Services is off: Tap the message, tap Turn On in Settings, then turn on Location Services.
- If Maps displays a message that Precise Location is off: Tap the message, tap Turn On in Settings, tap Location, then turn on Precise Location.
Cellular data rates may apply (see View or change cellular data settings on iPhone).
Note: To obtain useful location-related information in Maps, leave Significant Locations turned on in Settings
> Privacy & Security > Location Services > System Services."
We hope this helps you.
Take care!