The most well-known type of reef is a barrier reef. Barrier reefs can be enormous. They form parallel to coast lines. Other types include atolls, apron reefs and patch reefs. Atolls fringe submerged volcanoes.
Apron reefs form on shallow undersea slopes, away from land masses.
The coral bed at the Falls is a patch reef. Within the Interpretive Center exhibit gallery, the marine diorama can be found. The diorama was laid out to allow one scene to merge into the next. Tropical reef environments have always shared similar characteristics, including warm water, high angle of solar radiation and similar meteorological conditions. Coral does not grow well in cool water and therefore does not form reefs outside of the tropics.