Location history

Location Services uses GPS and Bluetooth (where those are available) along with crowd-sourced Wi-Fi hotspot and cell tower locations to determine your device’s approximate location.

Significant Locations: Your iPhone and iCloud connected devices will keep track of places you have recently been, as well as how often and when you visited them, in order to learn places that are significant to you. This data is end-to-end encrypted and cannot be read by Apple. It is used to provide you with personalized services, such as predictive traffic routing, and to build better Memories in Photos.

Your device's last known location is available for one day. If your device is offline or can't connect to Find My [device] for more than 24 hours, you won't be able to see the last known location.