You can show a lot of history in an area by layering the names. If elf cities have names like "Sindariel" and "Fianlorien" and dwarf cities have names like "Borok-Dor" and "Ghor-Khalesh", then an elvish city named Ghorkashundiel on the border of a neighboring dwarf kingdom hints that it wasn't always elvish. If the PCs have to go down into the sewers to chase a monster, they probably would have a fridge logic moment when they notice that the tunnels all have carvings of bearded faces.

You can see this everywhere in the real world. Almost every place in the Americas is named in a language not spoken by the people currently living in that place, usually with altered pronunciation (such as "Kanata" becoming "Canada"). The English name of many Native American tribes is the name they were called in the language of another tribe: when the European settlers encountered a new tribe, they asked a tribe they already knew "Who are those guys?"

This happens with places too. There are a lot of rivers with names that just mean "river" in another language. My favorite example is a hill in northwest England. People from the south moved north and asked "What's that?" and were answered "Penn", so they named it "Penn Hill" in their dialect. Then much later, new people come from the east and ask "What's that?" and the answer is "Tor Penn" so they call it "Torpen Hill" in their language. Eventually, the Angles, Saxons, and Jutes merged their languages into one Anglo-Saxon (sorry Jutes!) language and later the Normans come to add in their fancy French vocabulary and everybody started calling big bumps smaller than mountains "hills", so "Torpenhau" became "Torpenhow Hill", which means "Hill-hill-hill Hill".