The irresistible appeal of caves is obvious from the enduring popularity of commercialized show-caves: dark, mysterious and beautiful, the hidden world of caves draws the visitor ever deeper. However, although it is 'one small step' from the concrete path to the rugged cave floor and from tourist to caver, it is a step that most are reluctant to take. Those few who do venture into the wild cave discover a world of spectacular halls, grottoes, rivers and waterfalls.