The Cueva de Nerja, or Nerja Caves, are a three-mile series of caves near Nerja in Malaga province, southern Spain.
Today, visitors can take a 45-minute tour of the “public gallery” to see fantastical formations of stalactites, stalagmites and other speleothems – shapes and structures caused by mineral deposits.
So far, 589 prehistoric paintings have been discovered in the caves (modern visitors cannot visit those areas for conservation reasons).
Prehistoric visitors mostly burned one type of pine to light their way, the carbon analysis revealed.
“I think the magnitude and geological beauty of the Nerja Cave must have overwhelmed its prehistoric visitors, just as it overwhelms us today,” she said.