The architecture of Scotland in the Middle Ages includes all building within the modern borders of Scotland, between the departure of the Romans from Northern Britain in the early fifth century and the adoption of the Renaissance in the early sixteenth century, and includes vernacular, ecclesiastical, royal, aristocratic and military constructions. The first surviving houses in Scotland go back 9500 years. There is evidence of different forms of stone and wooden houses exist and earthwork hill forts from the Iron Age. The arrival of the Romans led to the abandonment of many of these forts. After the departure of the Romans in the fifth century, there is evidence of the building of a series of smaller "nucleated" constructions sometimes utilizing major geographical features, as at Dunadd an