|
 In
some places beneath the earth's surface lies a secret world. Waterfalls,
lakes, rivers, and beautiful columns of rock are hidden away where few
people will ever see them–in caves.
Caves
are giant holes running horizontally underground. Holes plunging vertically are called potholes. The largest caves, called caverns, are found in
ground made of limestone.
Some caves form huge underground networks. The
longest cave system ever explored is the Mammoth-Flint Ridge system in
Kentucky. It includes more than 190 miles (306 km) of passages, lakes,
rivers, and open areas.
What is a Cave |
How caves are formed? |
Cave
Landscapes |
Stalagmites & Stalactites |
Cave animals |
People and caves |
