The Iglesia de la Asunción is the oldest church in the Canaries, founded in the mid-15th century and rebuilt several times since. The current structure is a modest whitewashed building on the Plaza de las Américas, its Mudéjar-influenced tower visible from the waterfront. The interior is simple — bare whitewashed walls, a wooden ceiling, and a handful of religious paintings — but the atmosphere is genuine and the connection to the town's history palpable.
The church stands at the centre of the original colonial settlement, alongside the site of the Peraza family residence and a short walk from the Torre del Conde and the Casa de Colón. Together they form a coherent historic quarter that makes San Sebastián one of the most historically significant small towns in the whole of the Spanish archipelago.