1. Unit 6 – Mammoth Cave Mammoth Cave National Park is a U.S. National Park in central Kentucky. It is the longest cave system known in the world. U.S. National ParkKentuckycave Here you can see the waterfall into historical entrance of Mammoth Cave.

2. Unit 6 – Mammoth Cave Many cave creatures are uniquely adapted to their environment, which may seem strange to us but is normal to them.

3. Unit 6 – Mammoth Cave Here, a cave cricket sits on a limestone in Mammoth Cave. (From tip of front leg to tip of back leg, the cricket is about 3 inches long.)

4. Unit 6 – Mammoth Cave Broadway of Mammoth Cave is one of the many huge passageways dissolved in the layered limestone of the park. The cave is immense; this room is several stories high.

5. Unit 6 – Mammoth Cave In Mammoth Cave you can see gypsum flowers. Limestone (calcium carbonate) often has a little gypsum (calcium sulfate), which makes formations with this distinctive appearance.

6. Unit 6 – Mammoth Cave In Mammoth Cave there are channels in limestone produced by dissolution of limestone in acidic groundwater.

7. Unit 6 – Mammoth Cave Passage in Mammoth Cave probably started as a vertical crack, which was widened by dissolution of the limestone rock into acidic groundwaters flowing along the crack.

8. Unit 6 – Mammoth Cave The National Park Service offers several cave tours to visitors. Many of the most famous features of the cave, such as Grand Avenue, Frozen Niagara, and Fat Man's Misery, can be seen on lighted tours ranging from one to six hours in length. Two tours, lit only by visitor- carried paraffin lamps, are popular alternatives to the electric-lit routes.National Park Service On the picture you can see Frozen Niagara section of Mammoth Cave.