L'Observatorie - Paris, France
Posted by: 
Metro2
N 48° 50.223 E 002° 20.201
31U E 451325 N 5409553
Construction of this Observatory was completed in 1671- predating England's Greenwich Observatory.
Waymark Code: WMD1RF
Location: Île-de-France, France
Date Posted: 11/07/2011
Views: 18
This historical marker is located to the left of the entrance to the Observatory. At that time, Paris laid claim to the site of the grand meridien..a photo of which is shown on this Wikipedia page (
visit link)
That webpage also informs us:
"The world's first national almanac, the Connaissance des temps was published by the observatory in 1679, using eclipses in Jupiter's satellites to aid sea-fairers in establishing longitude. In 1863, the observatory published the first modern weather maps. In 1882, a 33 cm astrographic lens was constructed, an instrument that catalysed what proved to be the over-ambitious, international Carte du Ciel project.[citation needed]
In November 1913, the Paris Observatory, using the Eiffel Tower as an antenna, exchanged sustained wireless (radio) signals with the United States Naval Observatory to determine the exact difference of longitude between the two institutions."
The marker informs us, amongst other things, that Urbain Le Verrier
discovered the planet Neptune from this site.