We review the method developed in Pisa to determine the topological
susceptibility in lattice QCD and present a collection of new and old results
obtained by the method.Comment: 10 pages, 7 figures. Contribution to "Sense of Beauty in Physics - a
volume in honour of Adriano Di Giacomo" (Pisa University Press, Pisa, 2006),
on the occasion of his 70th birthda