This reminds me of Werner Herzog's documentary about similar cave, but in France "Cave of Forgotten Dreams". The thing with Herzog is that he captures eccentricities of people and you can see people going around that place walking and listening to the ground to hear if there are more caves like that. I imagine people in Spain doing the same.
teachings of the Bible are so muddled and self-contradictory that it was possible for Christians to happily burn heretics alive for five long centuries. It was even possible for the most venerated patriarchs of the Church, like St. Augustine and St. Thomas Aquinas, to conclude that heretics should be tortured (Augustine) or killed outright (Aquinas). Martin Luther and John Calvin advocated the wholesale murder of heretics, apostates, Jews, and witches. - Sam Harris, "Letter To A Christian Nation"
