Haus zum Cavazzen is the name of a famous building in Lindau. More info here: http://www.kultur-lindau.de/museum/der-cavazzen/
But what does this name mean, and why zum is used together with what seems to be a proper name?
This was a usual way to make buildings (or establishments within) unique by giving them a patron or symbol, i.e. to name them.
A maybe related example would be the U.S. Ambassador to the holy See.
The proper name "Cavazzen" led back either to some money lender called "Kawertschen" from Lombardy who established between 1286 and 1375 in Lindau or to a family called "von Kawatz" who lived there since 1553 in the locality of that building.