Final answer:
Brochs are ancient circular structures found in Scotland, dating back to the Iron Age around 2,500 years ago. They served as fortified dwellings and provided protection to the inhabitants.
Step-by-step explanation:
Brochs are ancient circular structures found in Scotland. Bryson visits brochs in Scotland during his travels. Brochs are unique to Scotland and date back to the Iron Age, around 2,500 years ago. They were made of stone and were used as fortified dwellings, offering protection to the inhabitants.