# prime meridian

> line of longitude, at which longitude is defined to be 0°

**Wikidata**: [Q3401774](https://www.wikidata.org/wiki/Q3401774)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Prime_meridian)  
**Source**: https://4ort.xyz/entity/prime-meridian


## References

1. [Source](https://www.escapadesalondres.com/pages/tout-au-long-de-l-annee/les-autres-activites/l-observatoire-royal-de-greenwich-et-le-meridien-d-origine.html)
2. [Source](https://support.esri.com/fr-fr/gis-dictionary/prime-meridian)
3. [Source](https://www.techno-science.net/glossaire-definition/Meridien-de-Greenwich.html)
4. Freebase Data Dumps. 2013