Petrella Guidi Castle is a formidable medieval fortress dating back to at least the 11th century, dominating the Marecchia Valley. The primary monument is the castle complex itself, featuring a massive polygonal keep, imposing stone walls, and a prominent watchtower (torrione), a classic example of medieval military architecture designed for strategic control. While it served as a residence for powerful families like the Guidi and the Malatesta, it is more a fortress than a refined aristocratic palace. The castle and the surrounding village often host historical reenactments and cultural events, especially in the summer, bringing the ancient walls to life. Nearby attractions are plentiful in the Montefeltro region: visit the charming town of Sant'Agata Feltria, famous for its truffle fair and Rocca Fregoso fortress; explore Pennabilli, the spiritual home of poet Tonino Guerra; and marvel at the imposing Fortress of San Leo, perched atop a massive cliff, famously imprisoning the alchemist Cagliostro.