premise: The d'Estes' Palazzo dei Diamanti (9,000 pointed pieces of diamond-shaped marble on its walls) houses the Pinacoteca Nazionale, with notable works of the Ferrara masters Cosmy Tura, Ercole de' Roberti, Garofalo, and Dosso Dossi.
hypothesis: Pinacoteca Nazionale has been empty for the last 20 years.