Alatri

Alatri is a town in the province of Frosinone, in the Ciociaria region of Lazio, in the Ernici Mountains. Its protohistoric origins trace to the Hernici, an ancient Italic people who inhabited the Sacco valley before Rome's expansion, and ancient Aletrium was one of their principal centers. The town is best known for its acropolis, encircled by cyclopean walls of massive unmortared limestone blocks dating to around the 7th century BC — considered the most complete and best-preserved example of this type of fortification in Italy.

The acropolis and its cyclopean walls, roughly 2 km in circumference, are the principal sight, entered through two monumental gates (Porta Maggiore and Porta Minore) each formed from a single massive lintel stone. The town's cathedral now stands atop the ancient acropolis site.