Situata a 4 km dall'abitato di "Numana alta" e dal porto, Marcelli sorge su una palude (bonificata dai signori di Numana) e si estende sino al fiume Musone, limite meridionale del comune. ###>Located from the town of Numana, Marcelli was built on a swamp that was reclaimed by the lords of Numana and extends to the Musone River, the southern boundary of the municipality.