The Phrygians crossed the straits into Anatolia from Macedonia and Thrace. In Greek times, the Phrygians' most north-westerly settlement, was Keramon Agora, where a branch of the Royal Road left Lydia to strike northwards. Phrygian architecture was well developed. Vitruvius describes their houses as built of wooden logs laid in a trench excavated in a mound and then covered with reeds, brushwood and earth. Phrygians had reached considerable mastery in several crafts, whether as bronze-workers accomplished in both casting and raising, or as expert cabinetmakers and weavers, as workers in ivory, as makers of woollen felt or as weavers of linen, hemp, mohair, and perhaps also tapestry. Survivals of the Phrygian language linger into Roman times, occurring in bilingual form with Greek translations on tombstone inscriptions. The Phrygians' religion clearly consisted of at least two strata: primitive Anatolian and Indo-European. In the Early Iron Age, the mineral deposits of Anatolia had already been famous for one thousand years.