Santua

Santua is the largest and most populated of the 23 islands of the Duchy of Biscay, accounting for nearly 80% of the duchy's total land area and at least 95% of its population. It is over five times the size of the duchy's second-largest and second-most populous island of Terpoatrea.

Santua's southernmost cape encloses a large bay which shelters the city of Portua, the duchy's capital, largest city and primary port. Portua was home to 558,306 people according to the December 2020 census, accounting for nearly a third of the duchy's population. The city sits at the centre of a metropolitan area home to nearly a million people, over half the duchy's total population.