The carbon dioxide gas found in air dissolves in water running in rivers or water from springs,forming an acid,this acid reacts with stones,especialy limestones,when this acid water spreads on a limestone,and the limestone absorbs it,the acid water starts to react making holes in the limestone,therefore a cave or grotto is formed.

This topic focuses on the interfernce of chemicals in our daily life.

how come caves sometimes are long

well,sometimes this acid is concentrated,helping increase the size of the cave or a big amount is produced everyday(by nature) which also makes the reaction continous so the cave is deeper and deeper.

[img][/img]

I love going to the meramec caverns, here is the website for it http://www.americascave.com/index.php

Wonderful.
By the way take a look at this site http://www.lebguide.com/lebanon/touristic_sites/lebanon_touristic_sites_jeita.asp