expression
upon (in place names)
A katakana rendering of the English preposition 'upon', used as a component in Japanese place names, often in fantasy, fictional, or stylized contexts. Not used as a standalone word.
「ストラトフォード・アポン・エイヴォン」はシェイクスピアの生まれた町です。
'Stratford-upon-Avon' is the town where Shakespeare was born.
ゲームの舞台は「リバーサイド・アポン・レイク」という架空の街だ。
The game is set in a fictional town called 'Riverside-upon-Lake'.