In Assassin's Creed II, Ezio helps restore the villa and town of Monteriggioni in Tuscany.
Monteriggioni is the Auditore family's fortified estate and the central headquarters for much of Ezio's campaign. After arriving there, Ezio works with his uncle Mario to develop Villa Auditore and improve the surrounding settlement. Rebuilding shops and services generates income and makes the town a more useful base.
The location is based on the real medieval walled town of Monteriggioni in Tuscany, near Siena. Its distinctive defensive walls and towers still exist, although the game adapts the town and villa for gameplay and fiction. The historical setting helps connect the fictional Auditore family to recognizable Renaissance Italy.
Monteriggioni returns in Assassin's Creed: Brotherhood, where it is attacked by Cesare Borgia's forces early in the story. That later assault is separate from the restoration work in Assassin's Creed II. Forlì is another Italian city visited in the game, but it is not Ezio's villa headquarters.