Of course I'm not a native speaker and you shouldn't listen to me:) Yet I felt like asking if it's possible to be: "The city is located 2450 meters above sea level"?

The correct noun is altitude - the altitude of the city, not the "height". Yes, the adjective is "at". The city is at an altitude of 2450 meters/metres. We are skiing at 1650 (metres) at Courchevel.

This city is located ...... at 2450 meters .

You can use "about" I think

ben'in cevapi doğrutür.