San Sebastián's Old Town, Parte Vieja, is the historic heart of the city, wedged between the Urumea river and the harbour. Once fortified, this compact neighbourhood remains the cultural and gastronomic epicentre, famous for its extraordinarily high concentration of pintxos bars—reputedly the world's greatest density. It's where locals gather to sample the region's finest food and drink, making it essential to visit for an authentic taste of Basque life.