When visiting this town on the Northern side of the Madonie, you can start from its oldest part, piazza Mazzini, where the XIV century Mother church is; you can also visit the nearby late medieval church of San Michele. Crossing Corso Vittorio Emanuele, you get to the church of the Rosary, where the marble sarcophagi by Santacolomba and a XVI century painting of the Flemish school are. In the highest and oldest part of the built-up area, you may find the remains of the Castle. The area between Isnello and Gratteri features many a cave; among the most remarkable ones there is the Abisso del Vento (Wind Abyss), rich in mineral deposits and underground lakes. 
The frittella (vegetable dish made with fresh green fava beans, peas, and sometimes artichoke hearts and scallions) festivaltakes place in April and the green fava bean festival in June. 
Websites: http://www.parcodellemadonie.it/home.htm