Defining the Optimal Ranges of Tourist Visits in UNESCO World Heritage Caves with Rock Art: The Case of El Castillo and Covalanas (Cantabria, Spain) - Fernandez-Cortes, A.; Palacio-Perez, E.; Martin-Pozas, T.; Cuezva, S.; Ontañon, R.; Lario, J.; Sanchez-Moral, S. (Applied Sciences (Switzerland), 2025)