The most common types of caves are those formed by the erosion
of limestone which is soft in nature. Carbon dioxide present in
the water reacts with limestone deposits wearing away thick
deposits. Sometimes water gathered on the surface seeps down
causing small openings in the roofs of caves. These openings are
called "sink holes". Caves often have several
galleries or layers, one above the other. Underground streams
that may have formed these caves sometimes find lower levels to
flow though forming these galleries.
In certain cases the water dripping from
the roofs of the caves have some mineral deposits mixed with them.
When the water evaporated the mineral deposit is left behind and
form icicle shaped structures that are attached to the roof of the
cave. These structures are called "stalactite". Water dripping along
these stalactites to the floor builds up a column called a
and Stalagmites formed in a cave