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Paris Hidden Gems

Secret Paris Underground: Parisian Metro, Catacombs of Paris tour, Lutetia and other Paris Hidden Gems

Secret Paris, Paris Souterrain, Paris Underground, Hidden Paris, Paris Travel Inspiration, Paris Off the Beaten Path, Things to do Paris #paris #moveablefeast #secretparis

Paris really is a tale of two cities. There is the City of Light, above ground, with its beloved Eiffel Tower or Louvre Museum. This is the city that the world sees and loves. But there is also an underground Paris, (le Paris Souterrain or Hidden Paris), lesser known by visitors and locals and which is much more than the Paris Catacombs.

Although we enjoy walking the streets of Paris, the secret Paris underground city is an important subject of our quirky explorations. Indeed, the magnificent City of Light hides at least 130 kilometers of abandoned tunnels and secret places running below its streets.

This is our personal compilation of some really cool Paris hidden gems: from Roman Lutetia (Paris’ first settlement) to the current Parisian Metro, there is something for every taste.

There is no need to say that these Secret Paris underground tours are great things to do in Paris on a rainy day or when it’s too hot outside 😉

Secret Paris Best Reads

We recommend

Most of these places are cold and humid, with slippery floors. We recommend bringing an extra layer, sneakers, and a scarf. Bring also a bottle of water (or warm tea or coffee) with you.


Metro in Paris

With a daily ridership of 4.16 million (2015), the Parisian Metro is the most known part of underground Paris. The metro of Paris has 300 metro stations spread all over the city, you can see our favorite metro stations here. BUT the Parisian Metro also hides 18 abandoned metro stations. Amongst them, Porte des Lilas is the most popular hidden metro station because it is the one used for shooting movies. However, our favorite hidden metro station is Saint-Martin metro station. Located in the 2nd arrondissement in Paris, this station was closed after the Second World War due to its proximity of Strasbourg-Saint Denis metro station. This place is a step back in time because it still keeps the aesthetics and ceramic decoration of the thirties and its panels still advertise the products of that time. Saint Martin, being the ceramic workers’ saint patron, these workers executed really beautiful ceramic decoration, with 3D motifs for this metro station.



See Paris Differently

The Paris Catacombs are underground quarries which were reused years later for stocking the bones of disappeared cemeteries in Paris. Paris Catacombs tours and visits are the most popular Paris underground tours amongst tourists, probably because of its original, spooky character. We must agree that the inscription at the Catacombs entrance  « Arrête! C’est ici l’empire de la mort » (=stop, here it’s the empire of Death) is very impressive, and all those skulls piled forming beautiful designs are fun. If you want to visit the Paris Catacombs, we recommend buying a Catacombs skip the line ticket or a Paris Catacombs Tour online in advance. Queues in front of Paris Catacombs entrance are always very long.

READ MORE –  Skip the Line Paris Catacombs and other Paris Tourist Attractions

BOOK: Skip the Line Paris Catacombs Tour with Special Access



some fleur de lis survived in Paris underground

The famous Paris catacombs only represent the 0.5% of the Paris underground city. There are other places less easy to reach, sometimes forbidden places, which years ago were the object of clandestine parties and other kinds of meetings. A great, more local (and totally legal!) alternative to Paris Catacombs are the Carrières des Capucins. This limestone quarry located below Paris 14th, Paris 13th and Paris 5th is maintained and enhanced by a non-profit association, in the form of a museum. Their unusual and rather confidential torchlight tours unveil part of the city’s exceptional industrial heritage (the world of underground quarries) and some interesting curiosities. This tour (in French) is also a step back in time: indeed, under the streets of the 21st century, the Paris of the XVIIIth century still exists inside the Quarries of the Capuchins.

READ MORE – Paris Underground: les Carrières des Capucins



paris sewer museum

This is a quirky but very interesting visit that we always recommend. The Paris Sewer Museum details along 500 m of their tunnels the history of the sewer system and water in Paris from the former Roman city of Lutetia, Paris’ first name, to its modern structure (XIX century). The museum also explains the sewer workers’ role and the methods of water treatment. We were happy to know that Paris is the city which has the biggest and most modern sewer system in the world!

BOOK: Exclusive Subterranean Paris Small Group Tour



Everybody knows about Paris Lutetia’s thermae, located inside Cluny Museum in the 5th Arrondissement of Paris. But how Romans brought water from the Seine river up to these public baths? Romans had also an efficient sewer system and you can see a part of it just below the Roman baths. These underground galleries can be visited only during the museum’s (unusual) guided visits to the Roman Baths and Underground Galleries. The visits are in French but even if you don’t speak the language we would not miss the opportunity to see this hidden Roman heritage. Cluny Museum will be closed for works from 1st March 2018 to Mid-July 2018. If you are visiting Paris after these dates, you can check their scheduled guided visits here.



During the XVIIth century, King Henry IV of France ordered to build a new aqueduct to bring water in Paris left bank. This new aqueduct, known as Aqueduct Medicis, was 13 kilometers long and could be accessed for inspection through 27 different inspection chambers called regards. Chamber #27, also called Grand regard de l’Observatoire, was the inspection chamber at the end of the aqueduct and above this regard, the house for the Intendant General of the Waters and Fountains of the King (commonly known as le Fontainier) was built.

What is interesting about this place is not the house itself but what’s below the ground. At this point, the waters of the aqueduct were finally gathered before being distributed to the city. The grounds of the house were divided into three different vaulted halls, each one with its own distribution pool. The king’s distribution pool was obviously the biggest. Then, there was also a distribution pool for the religious men and their monasteries and convents. Finally, the third distribution pool (the smallest) brought water for the rest of the city. Later in 1845, engineers Lefort and Mary built a large reservoir-hall to store the overflow of water that drains at night. This tank-hall is connected to the old distribution pools through a large pipe. Crossing the pipe from the old distribution pools to the tank-hall is the most celebrated part of the guided visit, especially by kids.

On the picture above you can see the arrival of water from the aqueduct to the distribution pool for the religious men. La Maison du Fontainier can be visited during special events like les Journées du Patrimoine.



Today 18 regards (=inspection chambers) still exist in the city but only eight are still visible and le Regard de la Lanterne is the most beautiful of all. This cylindrical, stone building located in Paris 19 was built during the XVIth – XVIIth century as the main inspection chamber for Belleville Aqueduct. This aqueduct was bringing in the past water in Paris right bank from Belleville hills.

We live not far from this little construction and we were curious to know what was hiding inside. Finally, during the last Journées du Patrimoine we could go down and see the well and the underground pipes, beautifully illuminated for the occasion. This little regard is covered by a dome surmounted by a lantern which allowed the circulation of fresh air inside. Today this regard no longer has any technical function but it continues to receive water from the Belleville water table.



This is the most beautiful site of Paris Souterrain. Unfortunately, Montsouris Reservoir (Paris 14) is classed as “sensitive site” (this is an important water storage unit for the city) and guided visits are today very rare. Le Reservoir de Montsouris is a massive underground water storage facility built in 1874. It looks like a beautiful underground cathedral with arched stone walkways in every direction and filled with turquoise water. You can see more pictures of this spectacular site here.



Water in Paris, Paris Underground, Canal Saint-Martin

Photo Courtesy: @Marin d’Eau Douce


The Canal Saint-Martin was designed by Napoleon‘s engineers in the XIXth century to bring drinking water in Paris. The Canal connects the Bassin de la Villette to the Seine upstream with a drop of twenty-five meters. Canal Saint-Martin has nine locks and two swing bridges and it measures 4.5 km long, more than 2 km of which is underground. The canal’s underground part is covered by a vault which was illuminated every year by the Japanese artist Keiichi Tahara (he died on 6th June 2017 so let’s see what happens from this year). Tahara’s installations illuminated the vault unexpectedly at the passage of the cruise boats. This part of the canal is also frequently used for shooting films. Movies like Ratatouille or Queen Margot filmed some of their scenes here. The Canal Saint-Martin cruise is a beautiful boat cruise with a much more local feeling than the Seine river cruises. It is proposed by Canauxrama, Paris Canal, and Marin d’Eau Douce (only sometimes, on request).

BOOK: Paris from the water: Seine River and Canal Saint-Martin 2.5 hrs cruise



This is, in our opinion, the most fascinating secret of Paris. There are lots of mysteries and legends around l’Opéra de Paris. were just stories? On the book, Erik the phantom is a deformed architect who helped to build the Paris Opera while at the same time he secretly built below its grounds an underground palace for himself, with a vast subterranean lake. This lake really exists and it is located exactly below the opera scenario. Yes,  the ballet dancers are somehow dancing over the water!

When the opera’s foundation works started in 1852, the architects realized that they were digging into a marshy area where the groundwater was very high. Charles Garnier, the main architect, had the idea of incorporating a cistern into his design to redistribute the water and relieve the water pressure on the basement walls. The cistern is usually full of water, like a lake, to be used by firemen in case of fire.

We would really love to see this place by ourselves but only a few people have access to this subterranean lake. This means that the lake is not part of the Paris Opera guided tours but the building itself and its story are so fascinating that we recommend to visit it anyway.

READ:The Phantom of the Opera by Gaston Leroux

BOOK: Treasures of the Paris Opera Garnier Guided Tour

EXPLORE: wander around the hidden lake beneath the Paris Opera, by Google Curio-Cité


We hope you enjoyed exploring these Paris hidden gems with us. Which of these Paris underground sites would you like to visit right now?

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  • Paige W
    02/14/2018 at 4:56 am

    What a great guide to the Paris Underground. I had no idea that you could explore so much of their underground! The water reservoir looks interesting and spooky all at once.

    • WorldInParis
      02/15/2018 at 3:50 pm

      Yes, the water reservoir is a very cool place. Actually all those places are very cool 😉

  • Sandy N Vyjay
    02/13/2018 at 5:59 pm

    The subterranean world of Paris is indeed fascinating. 130 Kilometres of sights and experiences below the ground is really intriguing. The hidden metro stations and the sewer museum are something that attracts me immediately. Hope to be able to cover these below the ground attractions when we are there next.

  • Indrani
    02/12/2018 at 12:24 pm

    I regret not doing this tour while in Paris. The whole underground network is so amazing.!
    Catacombs tour seems so interesting. And your pictures have a mysterious effect.

    • WorldInParis
      02/15/2018 at 3:51 pm

      Well, some of the places listed on the post are opened only during special occasions. If you want to do the Catacombs tour, I suggest to book in advance

  • Jody Robbins
    02/12/2018 at 1:10 am

    This really is secret Paris. I had no idea there were so many underground tours you could take. I’ve been to Paris 18 times but never any of these sites. Next time!

  • Carol Colborn
    02/11/2018 at 5:54 pm

    Looking at the photos, I can almost feel the cold and dampness. Thanks for the tips. This is the most comprehensive post on underground Paris I have seen. And it is amazing how extensive it is!

    • WorldInParis
      02/11/2018 at 8:11 pm

      I suffered the humidity a little bit at Carrières des Capucins because it is a long tour. That’s why I recommend an extra layer even if it is summer above. And a hot coffee in a thermos also comes in handy 😉

  • Medha Verma
    02/11/2018 at 1:16 pm

    I am not surprised that I have not heard of most of these places (except Catacombs, I’ve been there) and that’s the whole point about travelling with a local, these kind of hidden gems that tourists don’t hear of, can only be known by the locals! The St Martin Canal and the reservoir look pretty awesome. A trip to Carrières des Capucins is also right up my alley!

    • WorldInParis
      02/15/2018 at 3:52 pm

      Hope you will make it, Medha 🙂

  • Claire
    02/11/2018 at 1:16 pm

    That’s actually a really good idea to use an abandoned metro station for filming – it saves closing down one of the others! I love the 30s decor at the Saint-Martin station too. I had no idea there was so much going on underground in Paris! I’d heard about the catacombs before, and although that would be interesting I don’t think I could handle being underground with all the skeletons!

    • WorldInParis
      02/11/2018 at 8:08 pm

      Oh, don’t worry for the skeletons, they won’t bother you! 😉

  • Anu
    02/11/2018 at 6:01 am

    I was aware of the Catacombs tours ut rest of everything you say is an education. I love studying water management systems in ancient cities, so it is good to know of the underground sewage systems, tanks, and lakes. It seems Paris underground is as incredible as the city itself.

    • WorldInParis
      02/11/2018 at 8:08 pm

      Yes it is! And even more fascinating to explore than the city above 😉

  • Tanvi
    02/11/2018 at 4:27 am

    I didn’t know that Paris has an underground world like that.. I’d love to go to the museum of water & the catacombs..This post is bookmarked!

  • Brianna
    02/10/2018 at 10:12 pm

    I of course had heard of the famous catacombs in Paris but i had no idea there was over 130km of underground to explore. With secret metro stations and ancient Roman waterways it really is likes a while other world.