The Rocca is Riva's old moated fortress, sitting squarely on the lakefront like a blunt stone ship. Inside, the Alto Garda Museum covers archaeology, local history, landscape painting, and the long tug-of-war between Italian and Austrian influence around the upper lake.
It is the right first stop if you want Riva to be more than a pretty harbour. The building gives the visit its weight: you move through a real medieval stronghold, then step back outside into the light and wind of the lake.