"Broadway, in Mammoth Cave. One of the most-visited parts of Mammoth Cave National Park, the passage called Broadway, or "Main Cave", is a vast subterranean river channel, long abandoned by the waters that formed it. Near left center on the cave floor lie pipes made of hollowed tulip poplar logs, remnants of the nitre mining during the War of 1812. This view looks toward Rotunda and the Historic Entrance."