The relics of Saint Wenceslas are in which European capital's city cathedral?

my grandparents were from Bohemia, which is now part of the Czech Republic. I attended St Wenceslaus Church and School growing up so learned about St Wenceslaus. visited this site when in Prague years ago.

but no word about Wenceslas himself, why he's a saint...

sollu bey

Should have known it was Praug.