Leaning Tower of Pizza is a special limited item (was available until March 28, 2011) that can be obtained by collecting 40 Italy Tokens as part of the Euro Challenge (Challenge Supremo!).
In Game description: "The date: January 5, 1172. The time: Pizza time! This replica of the famous Italian landmark will remind people everywhwere that where there's a leaning tower... there's pizza waiting to be eaten. Buon appetito!"