Aste Nagusia — Semana Grande de San Sebastián
Aste Nagusia is the main festival of Donostia-San Sebastián, held around 15 August (Assumption Day). In 2026 it runs from 8 to 15 August — nine free days that kick off with the cannon shot in Alderdi Eder. Its global trademark: the International Fireworks Competition, drawing ~90,000 people each night over La Concha bay.
What it is and when: nine days around 15 August
Aste Nagusia (Semana Grande) is Donostia's main festival, always held the week of 15 August — the Assumption holiday — from Saturday to Saturday. In 2026 it falls between 8 and 15 August: nine days of mostly free programming (the 2025 edition packed 387 events across 34 venues). It opens with the cannon shot from the gardens of Alderdi Eder, next to City Hall, on Saturday at 19:00, and closes with the burning of Marijaia. One important heads-up: although it overlaps with La Concha's beach season, this is NOT a beach festival. The real draw is the fireworks over the bay, the txosnas of Sagüés and the streets of the Casco Antiguo. Exact dates can shift year to year, so always confirm the programme on the official Donostia Kultura website before booking your trip. The cannon-shot day is, by far, the most crowded.
The opening cannon shot and the fireworks over La Concha
The starting gun is the cannon shot from Alderdi Eder on Saturday at 19:00 — expect packed crowds, so arrive early or find an open spot on the Boulevard. The headline event, however, is the International Fireworks Competition (60th edition in 2026), considered one of the three most important in the world alongside Montreal and Macao. Each night at around 22:45, a pyrotechnics team from a different country fires a 25-minute display over the bay in front of some 90,000 spectators who vote for the Concha de Oro. In 2026 it is scheduled from 9 to 16 August — check the official website each season to confirm. Best free spots: Playa de La Concha (full immersion; arrive before 21:30 for the front row), the Paseo, the Muelle, Ondarreta, the Peine del Viento and the viewpoints on Monte Urgull, ideal for photography. If it rains, the show is rescheduled to the following day at 19:30.
Txosnas of Sagüés: the local, late-night side
The popular soul of the festival beats at the txosnas of Sagüés, at the eastern end of the Gros neighbourhood, at the foot of Monte Ulia and next to the beach of Zurriola. These are the peñas' stalls: food, drinks in reusable cups and free concerts that start around 23:45, after the fireworks, and go on into the small hours. The vibe is young and local, a world away from the tourist postcard of La Concha — here it's all surf culture and nightlife. It's the authentic counterpoint to a Semana Grande that also caters heavily to mass tourism. One critical note: it is loud and packed, not a plan for young children at night. Use the daytime to go pintxo-hopping around Gros (streets Peña and Goñi, Zabaleta, General Arteche), quieter and cheaper than the Parte Vieja; on Thursdays there's pintxo-pote. To get back, búho night buses run reinforced services until between 02:30 and, depending on the night and line, 04:30–06:15 — check Lurraldebus/Ekialdebus timetables.
Basque traditions: giants, fire bulls, herri kirolak and Marijaia
Beyond the fireworks, Aste Nagusia showcases deep-rooted Basque culture. In the morning, giants and big-heads (giganteak eta buruhandiak) parade through the Parte Vieja to the delight of children. In Plaza de la Trinidad, herri kirolak — rural sports — take centre stage: aizkolaris chopping logs with axes in endurance contests, harrijasotzaileak lifting stones, and palankaris. As night falls, around 23:30, the fire bulls (zezensuzkoa) charge through the streets of the Casco Antiguo: frames loaded with pyrotechnics that a person runs through the crowd, launching sparks up to a metre and a half in the air. It's spectacular, but for exactly that reason NOT suitable for young children or anyone who doesn't want minor burns — keep your distance and wear clothes that won't catch fire easily. The figure that presides over the festival and is burned at the end is Marijaia, the 'Lady of the Festivals', a tradition that connects with the whole Basque festive ecosystem: aurresku, txistu, dantzak and tamborradas.
Frequently asked questions
When is Aste Nagusia and how much does it cost to get in?
Where are the best free spots to watch the La Concha fireworks?
Why is it so hard to find accommodation in San Sebastián in August?
Is Aste Nagusia a beach festival?
Some links on this page are affiliate links: if you book through them, Andelaria may earn a commission at no extra cost to you. Transparency & affiliate policy
Book tickets and tours: Aste Nagusia — Semana Grande de San SebastiánPlan your trip
Book the essentials for your trip to San Sebastián.
Other places in San Sebastián
Playa de la Concha
playaThe most beautiful urban beach in Europe, with its unmistakable shell-like shape and the elegant 2 km Paseo de la Concha. Flanked by Monte Urgull and the island of Santa Clara, it offers fine sand, calm waters and postcard-perfect views of Palacio Miramar. The absolute symbol of Donostia and the epicentre of Basque summer life.
Parte Vieja (Casco Histórico)
barrioA labyrinth of medieval streets rebuilt after the fire of 1813, home to the world's highest concentration of pintxos bars per square metre. The gastronomic and festive heart of Donostia: Plaza de la Constitución — with the numbered balconies of the former bullring — and the Basílica de Santa María are its architectural jewels.
Monte Urgull y Castillo de la Mota
castilloA 123 m hill crowning the old town, topped by the Castillo de la Mota (12th century) and a monumental statue of the Sacred Heart (11 m). Paths through gardens and cannon batteries lead to viewpoints with panoramic views over La Concha bay and the port. Free entry all year round.
El Peine del Viento
monumentoThree Corten steel sculptures by Eduardo Chillida (1977) anchored in the rocks at the far end of Ondarreta beach, where the city merges with the Cantabrian Sea. Architect Luis Peña Ganchegui designed the surroundings with granite paving and water jets that emerge with the tides. The defining masterpiece of 20th-century Basque art.
Monte Igueldo
miradorAt 181 m altitude, this offers the most spectacular views of La Concha bay and the Cantabrian horizon. You reach the top on the 1912 wooden funicular, one of the oldest in the Basque Country. At the summit, a charming century-old amusement park rounds off the experience. An unmissable stop at sunset.
Kursaal (Palacio de Congresos y Auditorio)
museoTwo cubes of translucent glass designed by Rafael Moneo (1999) on the banks of the Urumea river, winners of the Mies van der Rohe Award. Home to the San Sebastián International Film Festival (one of the world's most prestigious) and the Quincena Musical. An icon of contemporary Spanish architecture, dramatically lit after dark.
Tamborrada de San Sebastián (Danborrada)
fiestaLa Tamborrada is Donostia's patron festival: every January 20th — a fixed date, never moved — the entire city beats drums and barrels for exactly 24 hours, midnight to midnight. More than 176 adult comparsas (+20,000 people) march through every neighbourhood. UNESCO Intangible Cultural Heritage (2018). Free and open to all.
Festival Internacional de Cine de San Sebastián (Zinemaldia)
fiestaZinemaldia is Spain's most prestigious film festival and the only one with FIAPF Category A status, alongside Cannes, Venice and Berlin. Every third or fourth week of September, San Sebastián awards its Golden Shell. Watching the red carpet is free; screenings are ticketed, with seats from around €8.75 per session.