positioned on top of all other layers. The sub-styles of stylistic group A are numbered chronologically; that is, A1 is the oldest and A5 is the youngest. The Black series in particular introduced several artistic innovations that were carried forward into subsequent artistic styles. These include the introduction of both aerial and hierarchical perspectives, which would be incorporated into later artwork. It also introduced contrasting colors, in the form of black and dark purple, which were used to differentiate between separate representations, a method that would be used throughout the history of the cave art. Many of these influences would carry on in the styles of hunting scenes as late as 5,400 BC. Stylistic group A ended during the H1 eruption of the Hudson volcano, which took place around 4,770/4,675 BC and led to the abandonment of the Rio Pinturas Area. It is very likely that this eruption is what caused the end of this stylistic group. Stylistic groups B and B1 A new cultural group, lasting from around 5,000 BC until around 1,300 BC, created the art of what is now considered stylistic groups B (Río Pinturas II) and B1 (Río Pinturas III). Static, isolated groups of guanacos with large bellies, possibly pregnant, replace the lively hunting scenes that marked the previous group. These pregnant guanacos and their style and construction were first introduced as part of the Black series of Stylistic group A. Large groups of superimposed handprints, numbering around 2,000, in many colors, are associated with group B, as are some rarer motifs of human and animal footprints. In group B1, a subgroup of B, the forms become more and more schematic, and figures, human and animal, become more stylized; the group includes hand stencils, bola marks, and dotted line patterns. Stylistic group C Stylistic group C, Río Pinturas IV, begins around 700 AD and marks the last of the stylistic sequences in the cave. The group focuses around abstract geometric figures, including highly schematic silhouettes of both animal and human figures, alongside circles, zigzag patterns, dots, and more hands superimposed onto larger groups of hands. The primary color is red. Cultural significance and conservation Every February the nearby town of Moreno hosts a celebration in honor of the caves called Festival Folklórico Cueva de las Manos. Many tourists visit the cave, which is known worldwide. The number of tourists visiting the site has increased by a