Brother Pedro, the Saint
There is a volcanic cave on the Island that could easily have gone unnoticed but which has nonetheless become a popular place of worship. This is the cave of Brother Pedro, in Granadilla de Abona. This 17th century shepherd regularly used the cave to take shelter with his flock of goats, until he felt the call of religion at the age of 23. After dedicating his life to caring for the weak in Guatemala, he was declared a Saint in 2002.
Whether or not you are believer, a visit to the cave is an interesting experience, where you can see the countless religious relics, candles and offerings that adorn such a small space. The nooks and crannies in the walls are full of notes written by visitors who share their promises and wishes with Brother Pedro in the hope that he will help them come true. You might want to make a wish yourself while you're there.