The Arago Medallions of Paris

If you look down at your feet whilst wandering through the centre of Paris, you might just spot an Arago Medallion. These 135 bronze markers set into the streets cut a perfectly straight line through the city from Porte de Clignancourt in the north, down to Gentilly in the South. They represent the location of the Paris Meridian, a line of longitude which is considered the zero point of longitude.

They are named after François Arago (1786-1853), a French astronomer, mathematician, physicist and politician. He calculated the precise location of the meridian, where the Arago Medallions are presently marked. The Arago Medallions is also sometimes referred to as the Rose Line, a term invented by author Dan Brown for his book The Da Vinci Code.

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Drawing of a bronze Arago disc at the Louvre Paris
The Louvre Arago Medallion

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What Is The Paris Meridian?

Today, the universally accepted Prime meridian is the Greenwich meridian, which was established at the International Meridian Conference in 1884. Before this desicion, countries would set their own meridians. The prime meridian was standardised – except France, however, which abstained from the vote. The French stuck with the Paris Meridian until 1911 to keep time, and 1914 for navigation.

Installing The Arago Medallions

While now France (like the rest of the world uses the Greenwich Meridian) the city of Paris and the Arago Association decided to honour the Paris Meridian in 1994, commissioning Dutch artist Jan Dibbets to take control of the project. Each 12cm medallion bears the word Arago on each one, with pointers showing the direction north and south.

Where To Find Arago Medallions

There are 131 medallions that cover 9.5km (5.7 miles), which makes seeing them an extremely complex task. Many are placed in hard to reach areas, such as in private gardens or inside private buildings, such as l’Observatoire de Paris. Over time, others have been stolen, or been covered over. As they medallions are in a perfectly straight line, and Paris is a winding city of twists, turns and city blocks, sticking to the route can be a very long walk indeed.

However, there are some notable Arago Medallions which are easy to locate, if you’d like to get sample of the old Paris Meridian line.

Some places where you can find an Arago Medallion are:

  • The entrance of the Musée du Louvre, in the main courtyard (Cour Napoléon) where the Louvre pyramid is.
  • Inside the Musée du Louvre, in the Denon Wing (3 to be found).
  • In front of the Palais Royal (medallion removed/lost).
  • In the gallery of the Comédie Francaise.
  • Jardin de Luxembourg.
  • l’Observatoire de Paris.
  • Parc Montsouris.
  • In the Passage Richelieu.


Paris is packed full of other hidden treasures! Find out what they are in this guide!

The Arago Medallions are a fun little Easter egg to discover in Paris. And while they only take a moment to spot and appreciate (or all day, if you plan to follow the whole line!), the Arago Medallions are a fun glimpse into the history of Paris and of French cartography.

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