John, there are two casinos in Venice which belong to the same organization (municipality).
The old Casinò di Venezia is located at the Grand Canal at the Palazzo Ca'Vendramin Calergi.
Beautiful building from the 15th Century. There is a museum dedicated to the composer Richard Wagner who was allowed to stay in the building.

Than there is, what they cal, the American casino close to Marco Polo airport.
This is called Casino' Ca' Noghera.

I'm not sure of the opening hours these days.
The water taxi from Marco Polo airport to the Grand Canal is awesome.
Hope this helps.