blue holes
Underwater cave entrances
Blue holes are deep underwater sinkholes or caverns, typically found in coastal areas or shallow seas, that appear as dark blue circles when viewed from above.
The distinctive color comes from the dramatic depth contrast with surrounding shallow waters.
These geological formations often extend hundreds of feet down and may connect to underground cave systems.
Blue holes are popular diving destinations, though their depths and currents make them hazardous.
The Great Blue Hole off Belize is one of the world's most famous dive sites.
- cavernLarge natural underground chamber
- cenoteLimestone sinkhole revealing groundwater
- sinkholeUnderground collapse crater
- BahamasAtlantic island nation
- abyssImmeasurably profound depth
limestone · thermocline · water · karst · depths · deep sea · ocean floor · Caribbean · speleology · submersible · bottomless · underwater caves · sea caves · deep · endemic species · marine life · formation · dark
- cavescave, cavern, caves, caverns, grotto
- landformsmountain, cliff, valley, volcano, mountain ridge
- natural waterssprings, hot springs, streams, creeks, ponds
- diving spotsdive sites, night dives, reefs, shipwrecks, wrecks
- natural poolscenotes, natural pool, rock pool, plunge pool, cenote
- island hydrologywater table, aquifers, freshwater, brackish water, rainwater harvesting
blue holescoral reefs
Calcium carbonate marine structures
seamounts · atolls · barrier reefs · volcanic islands · sea stacks
blue, hole, hollow, blueprint, holes, blueberry, bluer, bluebird, hollows