A man walks during his visit to the Grotto of Marvels in Aracena, southwest Spain
A man walks during his visit to the Grotto of Marvels in Aracena, southwest Spain December 8, 2006. The Grotto of Marvels, lined with stalactites and stalagmites, is the most extensive cavern of the Iberian peninsula of calcareous formation. REUTERS/Marcelo del Pozo (SPAIN)