Introduction 

A cave is a cavity inside the earth which may be either natural or artificial in origin. Natural caves come into existence by the action of water or tectonic displacement. Since time memorial both natural and artificial caves have served humankind in various capacities.  

Caves are considered sacred if they are associated with Gods, Goddesses, deities or mythical and magical figures, saints and preachers. They are also considered sacred if they are source of sacred rivers and streams or house sacred animals.

The use of caves for religious practices by individuals and groups extends back in time for at least several millennia in India. The Buddha dwelled and meditated in caves, forests, and other kinds of natural sites, practices which became common for Buddhist monks and nuns during his lifetime and beyond. Whenever Buddhism spread beyond India into other parts of Asia the religious use of caves spread as well. The same was the case with Jain Thirthankaras and their followers. Caves serve monks and nuns as secluded and peaceful places for monastic life, meditation, and chanting. A holy person might dwell in a cave for merely a few days or for months or even years. (1)

Caves affect the environment in positive ways. They support a natural habitat for life forms that require consistent temperatures and dark living conditions. Caves provide a valuable, clean water source that’s naturally preserved in underground rock formations. As long as caves are free of human-initiated pollutants, they contribute to the environment in healthy ways and aid in the overall cycle of life. (2)

Sacredness associated with caves has played an important role in their conservation and thus helped in conserving the biodiversity. Indeed, sacred caves may be one component of a very ancient, widespread, and diverse system of sacred places throughout much of Asia which traditionally had far reaching significance for environmental and biodiversity conservation. 

Source

1.  http://www.soc.hawaii.edu/sponsel/Research/Research.html
2.  http://education.seattlepi.com/caves-affect-environment-6725.html