Cave painting falls under the heading of "parietal art," a term used to note any prehistoric art found on the walls or ceilings of caves. It includes five basic types of work, from stencils of handprints, and other hand and finer marks, to a number of abstract signs and symbols, figurative painting, engraving and relief sculpture. It also encompasses all petroglyphs and engravings. The term generally implies prehistoric art as coming from the dawn of early man, but can also be far more recent, into what is called the Holocene Period. This is an easing period of the Ice Age in which modern man currently lives and ice age boundaries place prehistoric art in a range of 40,000 years ago to approximately 14000 BCE. It is the El Castillo of Spain that makes the first claim on the oldest images created by members of the human race. The cave is 85 kilometers to the west of Bilbao, in a region of numerous caverns with prehistoric artwork. This "Cave of Castles" near the town of Puente Viesgo in the Cantabrian region of the country was unearthed over a century ago, discovered by Hermilio Alcalde del Rio in 1903. In its totality, El Castillo's art content comes to over 100 different images painted in charcoal and red ochre. They are generally in outlines and club-shaped figures, and date significantly later than the red disc. A simple red disc at the center of the Panel de las Manos has been dated to 40,800 years ago. The contention that the disc is the oldest artwork of Homo sapiens is based on uranium/thorium testing, which only gives the minimum age of its subjects. Carbon dating could not be employed due to the absence of organic pigment in stenciled hand outlines.
