The closest is Forte da Ínsua, 18 km north of the city centre; the most famous is Castle of Guimarães — #644 of 7,738 worldwide — 53 km south-east. The oldest dated site in the circle is Castro of San Cibrao de Las, founded 200 BC.
The 100 km circle reaches into 2 countries — Portugal (20), Spain (12).























