I don't believe that using the admin feature to log in as another user writes to the login history because otherwise it would cause the "Last Login Date" to be inaccurate but I could be wrong on that point. What's most likely happening is one of two things.
When using an ISP, it's entirely possible for your IP address to be logged coming from different locations based on the address that gets assigned to you when you connect to the internet. In that circumstance it's usually not too far from where you're located so a neighboring city is the most likely location you'd see.
If you use a VPN or a proxy, your connection is routed through a remote server that can be located anywhere in the world. Similarly, if you authenticate to Salesforce through a connected app, it's possible the connected app gives you a different location (for example, Dataloader will often show that you logged in through Internet Explorer on a Windows machine even if you never use IE). Most likely, you have logged in through a VPN or authenticated with a connected app to receive this login history.