Gaztelugatxe is a small island off the Basque coast in the Bay of Biscay.
These days it is connected to the mainland by a narrow path that includes a two-arched bridge and one of those staircases with an undeterminable number of steps; so far this morning I have seen every number between 229 and 241.
At the peak of the island is a hermitage dating to the 9th century. Opinions differ as to the date of the current building, but some say 11th century.
The hermitage is dedicated to Saint John the Baptist. Some say the name of the island refers to him, as if “Gaztelugatxe” were the Basque word for "Baptist." But wikipedia says it means something like "craggy fort" or "inaccessible strong place."
The first certain historical record of the hermitage comes from 1053, when the island was donated to a monk by the name of Zianno, apparently the abbot of the monastery of San Juan de La Peña in Huesca, by a Navarrese couple, Doña Tota Ortiz and Lieutenant Eneko López. But it was already by then an "old" or "ancient" place, and archaeologists have found the graves of monks dating back to the 9th century.
The place entered secular history during the fourteenth century while Alfonso XI, King of Castile was subjugating the Kingdom of Pamplona. In 1334 Juan Núñez de Lara, Lord of Bizkaia, defied Alfonso's army from this spot with (the story has it) only seven knights. The seven knights held out for forty days, after which the Castilians gave up and went elsewhere.
The place was taken and sacked by Sir Francis Drake in 1593. Drake is always referred to in Spanish sources as "the pirate Drake," which is what he pretty much was even though the English remember him differently. Just a year later the place was taken again by Huguenot sailors serving the King of France; after burning the hermitage they threw the hermit off the cliff.
If you visit there now you may be told that the place once belonged to the Templars, but so far as I can tell that is a myth. Really, not every cool religious site has Templar connections.
The most devoted followers of the shrine in modern times have been sailors, and the chapel contains main ex-votos they have left in thanks for surviving shipwrecks and storms. In the summer the place has many visitors. Sadly it is closed in the winter, so you cannot come out on a cold windswept day and imagine the hard lives of the 9th-century monks who came here to suffer for God.