Cute Young Blonde Girl Standing By The Pond With Trees

Some ponds have no surface outflow draining off water and ponds are often spring-fed. Hence, because of the closed environment of ponds, such small bodies of water normally develop self contained ecosystems.
Uses
In the Indian subcontinent, Hindu temples usually have a pond nearby so that pilgrims can take baths. These ponds are considered sacred. In medieval times in Europe, it was typical for many monastery and castles (small, partly self-sufficient communities) to have fish ponds. These are still common in Europe and in East Asia (notably Japan), where koi may be kept.