Ardea, ancient town of the Rutuli people and now a modern village in the Lazio regione, west-central Italy. It lies 23 miles (37 km) south of Rome. In ancient times it was an important centre of the cult of Juno. Ardea developed into one of the most important Latin cities and was a member of the Latin leagues of the 6th and 5th centuries bc. In 444 the town signed a treaty with the Romans, who, according to Livy, colonized it as a barrier against the Volsci. The decline of Ardea, from the 4th century onward, was hastened by malaria and the Roman civil wars under Marius and Sulla in the 1st century bc. Pop. (2006 est.) mun., 35,263.