Paulo Nazareth. Algebra

A line of coarse salt runs across the floor of the upper galleries. Seen from above, it traces a tumbeiro, the Portuguese name for the ships that carried enslaved Africans across the Atlantic. A measured drawing against a wall shows up to four hundred people packed into one hold, in the space you are walking through.

Around the salt sit twenty years of Nazareth's work, some never shown before. Notícias de América condenses his ten-month walk from Brazil to New York into photographs, notes and worn-out Havaianas. There are small paintings of Mediterranean migrant boats done like Dutch sea pictures, consumer products sealed in resin, and skulls from Brazilian anthropological museums. Tadao Ando's concrete cube is wrapped in dishcloths embroidered by the artist's mother.

Domus called the salt line one of the most radical interventions this building has faced. The €20 ticket also covers Palazzo Grassi, under-20s go free, and it's closed Tuesdays, last entry 17:00. Free mediators are in the rooms on Mondays, Wednesdays and weekends.