The town's name derives from the Latin "Cale". It is a town in the province of Pesaro-Urbino, situated on a plateau along the Bosso and the Burano, at the foot of the Serra of the same name and surrounded by mountains, including the Catria and the Pietralata. The town is dominated by a watch tower, the last remnant of the ancient fortress built by the architect Francesco di Giorgio Martini in 1481 on the orders of Frederick II of Urbino. It was destroyed a few years later by his son to prevent their seizure by Cesare Borgia. The building expresses a new structural design and like all fortresses designed by Martini, it was a well built stronghold.
The recovery of numerous artifacts dating back to the IV century B.C., evidence the ancient Roman and Sabine origins of the city center. Later it submitted the Byzantine rule. In the VI century, it was part of Pentapoli and was involved in the XIII century in the struggles between Guelphs and Ghibellines, suffering considerable damage. In 1289 it was rebuilt under the supervision of Arnolfo di Cambio, in the plain below and in the following years, the whole area submitted a period of great demographic and economic development. Domain of the Orsini, the Colonna, the Baglioni, the Gabrielli, the Montefeltro and the Tarlati, in 1613, it passed to the Church. In the following centuries it shared the same history of the whole region and Italian State.
- the Abbey of Santa Maria Nuova, of which the foundation date is unknown, it was rebuilt several times. It features a bell tower and a nave. Of the original decorations still a fragment of a fresco depicting the Madonna and Child dating from the XIV century and retains several Roman tombstones;
- the Abbey of San Pietro di Massa, mentioned in a document which dates back to 1115, was probably built in the year 830. Remains of the original building are still visible in the walls of the structure that today features a single nave plan. Inside it preserves a XVII century altarpiece depicting the Madonna del Rosario;
- the Cathedral, of ancient origins, has been altered several times over the centuries. Of the original building, rebuilt in the XIII century, remain a walled Gothic portal and the crypt;
- the Church of San Domenico which preserves within a real jewel of art: the Tyrants Chapel, decorated by Santi, father of Raffaello;
- the Church of San Giovanni Battista, which features a Renaissance style portal and inside several valuable frescoes and a decorated crypt;
- the Church of San Francesco, a Romanesque-Gothic style building, which houses inside frescoes from the XIV century;
- the Church of Santa Maria della Misericordia, which retains several famous artworks;.
- the Sanctuary of Santa Maria delle Stelle, built in 1495;
- the Church of Sant'Angelo Minore, dating back to 1362;
- the Church of Santa Maria della Misericordia;
- the XVIII century Church of Santa Chiara;
- the Church of San Bartolomeo;
- the Church of San Giuseppe;
- the Church of San Filippo;
- the Town Hall, built in the XIII century and refurbished in the XV century;
- Palazzo Berardi and other valuable buildings;
- the remains of the great Roman bridge;
- the Watchtower of the fortress;
- the Municipal Theatre.