Santua

Santua is the largest and most populous of the Duchy of Biscay's 23 islands, accounting for approx. 65% of the duchy's total land area and 80% of its population. Santua is nearly five times the size of the duchy's second-largest and second-most populous island of Terpoatrea.

Santua's southernmost cape encloses Gran Ensenada, a bay and natural deepwater harbour which shelters the city of Portua, the duchy's capital, largest city and primary port. Portua was home to 330,516 people according to the December 2020 census, accounting for nearly 20% of the duchy's total population.