The Cango Caves were first explored in 1780 by a local farmer who was lowered into the dark, bat-filled chamber, which is now named in his honor. The Van Zyl Hall, 107m (351 ft.) across and 16m (52 ft.) high, has some incredible million-year-old limestone formations, including the Organ Pipes. A second chamber was discovered in 1792, and a century later the caves opened as a tourist attraction. Regrettably, they were damaged in the 1960s and 1970s, when the floors were evened out with concrete; ladders, colored lights, and music were installed; and a separate entrance was opened for "nonwhites" (who had tours at different times).
Today the caves enjoy a slightly more respectful treatment, with wardens fighting an ongoing battle to keep the limestone formations from discoloring from exposure to lights and human breath (although their running commentary is a tad irritating). There are two tours to choose from: the hour-long standard tour, which departs every hour and visits six chambers; and the 90-minute adventure tour, which covers just more than 1km (a little over a half-mile), some of which must be crawled (under no circumstances tackle this if you're overweight or claustrophobic; have heart, knee, or breathing problems; or are not wearing sensible shoes and trousers).