Upon entering the cave, the first impression is made by a chaos of limestone formations, moist with water oozing from above, and then is immediately felt what is known as "the breath" of the cave. It has pure air and an even temperature of 52° to 56°, and this is maintained all the year round. In summer the relatively cooler air flows out of the entrance, while in winter the colder air outside is drawn in, and this makes the movement of "the breath," at once apparent from the difference of temperature and currents of wind when passing the entrance. For nearly a half-mile within are seen the remains of the Government nitre-works, the vats being undecayed, while ruts of cart-wheels are traceable on the floor. The Rotunda is then entered, a hall seventy-five feet high and one hundred and sixty feet across, beginning the main cave, and out of which avenues lead in various directions. The vast interior beyond contains a succession of wonderful avenues, chambers, domes, abysses, grottoes, lakes, rivers, cataracts, stalactites, etc., remarkable for size and extraordinary appearance, though they are neither as brilliant nor as beautiful as similar things seen in some other caves. But their gigantic scale is elsewhere unsurpassed. There are eyeless fish and crawfish, and a prolific population of bats. In the subterranean explorations there are two routes usually followed, a short one of eight miles and another of twenty miles. Various appropriate names are given the different parts of the cave, and curious and interesting legends are told about them, one of the tales being of the "Bridal Chamber," which got its name because an ingenious maiden who had promised at the deathbed of her mother she would not marry any man on the face of the earth, came down here and was wedded. Bayard Taylor wrote of this Mammoth Cave, "No description can do justice to its sublimity, or present a fair picture of its manifold wonders; it is the greatest natural curiosity I have ever visited, Niagara not excepted."