The Palazzo Cini is right next door to the Peggy Guggenheim but it is largely skipped by tourists and so they are giving discount passes at the Peggy.
The Cini family also founded the San Giorgio Island install. This is merely an earlier iteration of the Prada/Pinault concept. Cini was a rich industrialist collector who also had a religious bent. Two Palazzi were converted by his daughter for a pot pourri of paintings sculptures and porcelains.
There are some nice things (a della Francesca Madonna and child and a great Pontormo portrait of Two Friends) but the discovery for me is the superior circular staircase by Tomaso Buzzi which was added in the fifties. An Imaginary Architecture show of drawings is up to coincide with the Biennale.