How to find the famous Paris “Rose Line”

This is a blog post about how to find the French Meridian Line, mapped out by bronze medallions on the streets of Paris. You may have already heard The Earful Tower’s podcast episode on the topic, which is embedded below. This page is a visual guide to help you find more.

But first, what is the “Rose Line”?

First things first, it isn’t actually called the Rose Line. That’s just what Dan Brown called it in the Da Vinci Code, presumably because the “Arago Meridian Line” sounds a bit boring. The line was once France’s prime meridian, a line of longitude right through the centre of Paris, and essentially a semi-circle around the the world from north to south. It is from these lines that distance and time can be measured.

France’s meridian was calculated in the 17th century, and developed more precisely by astronomer François Arago in the 19th century. (That’s Arago pictured below, in the outfit described in the podcast).

This line held a long-standing rivalry against other meridian lines, all of which eventually lost out to the Greenwich meridian. The rest of the world accepted London’s prime meridian quite quickly, and the French took a little longer, eventually accepting it in 1911.

To pay homage to Arago’s work in France, Dutch artist Jan Dibbets installed 135 bronze medallions in a straight line across Paris (from north to south), following Arago’s meridian line and memorialising when Paris was once the “centre” of the world. Seeking out these disks is a treasure hunt through many of the most beautiful parts of Paris.

What can you find of these markers?

Publicly in Paris, you can find the bronze medallions nestled in some of the city’s streets. Each one has the word “Arago” written in the middle and an N to mark north, and an S to mark south, though they’ve not all been installed so N actually points to the north.

The line begins from the Porte de Montmartre in the north of Paris and crosses to the Cité Université in the south. Over the years, many of the medallions have been stolen but quite a few remain if you fancy embarking on a Paris scavenger hunt.

The best short walk to find the most? Six in one minute!

Right in the centre of Paris, there’s a cluster of six Arago medallions. Start in the Palais Royale and search for the small outdoor gallery called the “Péristyle de Chartres”. In front of a glass window, you’ll see your first, then simply walk for sixty seconds in the direction of the nearby Cafe de Nemours to find five more on the way.

If you snag a chair on the terrace of Cafe Le Nemours, you might be sitting above the sixth medallion hidden underneath the tables.

Follow the golden disc road until you reach the Louvre and the medallions will guide you through the courtyard – bonus points if you pop into the museum and find their hidden medallions (see the section below!). Finish your walk with a final disc across the Pont des Arts, to the right hand side near a bouquiniste. What’s more, you’ll be rewarded with a fantastic view of the Seine and the weeping willow at the end of Ile-de-la-Cité.

Arago in the Louvre Museum

Hidden among the famous masterpieces in the Louvre, you’ll find some more medallions scattered across the ground. We found four during our recent visit but there are most definitely two more hidden in a section that’s currently closed for renovation and another one that seems to be impossible to get to.

It’s much easier to find medallions above the Louvre, especially near the glass pyramids, where you can find several.

What’s in the observatory?

The Paris Observatory – to the south of the Luxembourg Gardens and usually closed to the public – was built for this line. It was here that most of this week’s episode was recorded.

If you ever make it inside, the second floor features a huge strip on the floor from the north to the south side of the room, marking the exact location of the meridian line. The line is covered by plexiglass and includes astronomical engravings and measurements.

The gardens of the observatory are lovely – like something straight out of Provence. The grounds feature several medallions too.

Check back on The Earful Tower in the coming days for more pictures from inside (and outside) this fascinating observatory.

Elsewhere in Paris

Of course, there are plenty more medallions to find. This blog post has really focused on the most central of them all, but they stretch all the way to the Paris ring road (the Périphérique) to the north and the south. There’s also a boulevard Arago near the observatory with a statue plinth, and another homage in the Parc Montsouris. Keep your eyes down and you’ll surely find some too!

That’s it for now! Be sure to listen to the podcast episode about these markers as it will give you a much deeper insight into the story. Thanks to Augusta Sagnelli for the observatory pictures. A huge thank you to the Patreon members who will soon get an insider’s look at this meridian line, and who have already seen a live video for next week’s episode on the letter B.

Enjoy the episode below, the start of the ABC-son, with A standing for Arago. I wonder what B will be!