The French language is full of surprises as you know! Here is a new one: there is one letter in the French alphabet, used for only one word of all the French words. Do you know which letter it is? And which word it is?
Answer: the French letter ù (u accent grave) appears only once in the French language, in the interrogative adverb / relative pronoun où which means where.
The purpose of this accent is not to confuse the word où with the word ou (same word but without the accent on the u), which means or. But the pronunciation of these 2 words is exactly the same.
Fun fact: on the French keyboard, there is a dedicated key for the French letter ù, even though it is used for only one word.