# blue hole

> marine sinkhole or cavern

**Wikidata**: [Q7180402](https://www.wikidata.org/wiki/Q7180402)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Blue_hole)  
**Source**: https://4ort.xyz/entity/blue-hole


## References

1. Freebase Data Dumps. 2013