Yes. In your sentence about the city you can use yet, but or however. 
 
I can come on Friday but I won �t be available on Saturday.
I can come on Friday, however I won �t be available on Saturday. 
I wouldn �t use yet in this type of sentence. However is more formal than but.
 
He �s been learning English for years but he still can �t remember his irregular verbs.
 
He �s been learning English for years yet he still can �t remember his irregular verbs.
He �s been learning English for years however he still can �t remember his irregular verbs.
 
All correct -But would be the most commonly used word in this example when speaking.