Why go
The contrast is legible in Parte Vieja: fortifications around Urgull recall the border stronghold, Santa María reflects eighteenth-century commerce, and 31 August Street marks the fire that forced much of the old quarter to be rebuilt. The church and street name make the commercial rise and the later destruction tangible within a short walk.
The full story
After the conquest of Iberian Navarre, San Sebastián stood close to a contested frontier between Spain and France. Its defences grew stronger, and local seafarers took part in both trade and privateering. In 1728 the Compañía Guipuzcoana de Caracas was founded, expanding commerce with the Americas. Its profits supported urban improvements, including work associated with the church of Santa María. The Napoleonic wars brought another sharp turn. French forces took the city in 1808. British and Portuguese troops stormed it on 31 August 1813 after a siege; the town was then looted and burned. The destruction did not erase the old street layout, but it explains why so much of Parte Vieja’s architecture is later than its medieval origins. The surviving 31 August Street carries the date in its name.