Cazis is a municipality in the Viamala Region in the Swiss canton of Graubünden. On 1 January 2010 the municipalities of Portein, Präz, …Cazis is a municipality in the Viamala Region in the Swiss canton of Graubünden. On 1 January 2010 the municipalities of Portein, Präz, Sarn and Tartar merged into the municipality of Cazis. Cazis is first mentioned in 926 as Cacias.