‘au stade de Wembley’ (at the Wembley Stadium) should translate in u stadiu di Wembley.

We face the issue of the translation of preposition ‘à’ since ‘au’ is short for ‘à le’ (to the), in particular when ‘à’ is followed by a noun phrase denoting a location. This occurs in the disambiguation of French ‘à’ which can can either translate into à (to) or into in (in).