How Do You Spell FORT KNOXES?
Pronunciation: [fˈɔːt nˈɒksɪz] (IPA) 
The correct spelling for multiple Fort Knox locations is "Fort Knoxes". This is because the plural of a proper noun with a singular form ending in "x" typically adds "-es" to the end. In IPA phonetic transcription, it is spelled /fɔrt nɑksɪz/. Fort Knox in Kentucky is a well-known example, and if there were multiple locations with the same name, they would all be referred to as "Fort Knoxes" in written communication.
