The small church on the rocks dates from the 10th century and seems to have come from the Knights Templar. It was donated in the year 1053 by Lady Tota Ortiz y Enneko López to the monk Zianno, of the monastery of San Juan de la Peña (Huesca), one of the most influential monasteries in the middle ages.
The island is a strategic spot for controlling the coast. In fact, history states that Gaztelugatxe constituted one of the bastions of resistance against the vanity and rapacious desire of Alfonso XI, the King of Castile. This dangerous enclosure was defended in 1334 by seven knights who resisted the attacks of a well organized army for more than a month. Having failed to siege the island, the Monarch withdrew humiliated. In 1593 it was attacked again and sacked by Francis Drake, whose troops plundered everything to be found in that sanctuary and threw the hermit off the cliff.
Today, the serenity of the island, the breathtaking views of the rugged coast, the relentless sea pounding against the rocks and the flocks of seabirds is what drives visitors to this not-so-remote island near the towns of Bakio and Bermeo. The best place to visit the island is during spring and autumn. Summer months are often crowded with visitors and the church is closed during the winter.