One thing I absolutely love about Europe (among hundreds of other things) is how easy it is to get around via public transportation. I'm also a huge fan of making the most out of a trip abroad so with that said here are some recommendations for side or day trips if you're staying in Paris.
1) Versailles:
The palace of Versailles is SW of Paris and was originally built as a hunting lodge for Louis XIV but because he wanted to keep his court tight-knit and close he moved everyone there which is how Versailles eventually became the royal residence and hotspot for all things chic, elegant and sophisticated. Several monarchs lived and reigned there including Louis XIV ('The Sun King'), Louis the XV and the ill-famed Louis XVI and his wife Marie Antoinette until the start of the French revolution in 1789.
This is a great day trip from Paris not only because of its fabulous history but also because it's just over 12 miles away, which makes it easily accessible. The metro in Paris is fairly easy to navigate; here, the metro lines serve the various arrondissements around Paris and the RER train system serves Paris and its suburbs (the Palace of Versailles is technically a Parisian suburb). To get there from Paris take the RER C, which runs along the seine river and get off at the Versailles stop (see map of metro).
Once you get there be sure to give yourself plenty of time exploring the various rooms that the King and Queen slept in and entertained guests. Each room is absolutely stunning in it's own right but nothing compares to the Hall of Mirrors, a long room filled with mirrors and chandeliers. Historically, this an important area because this is where the Treaty of Versailles was signed to end WWI. It's just gorgeous and breathtaking to walk through. Beyond the interior of Versailles are the gardens and beautiful fountains which hug the perimeter of the palace. Take some time walking around, getting lost among the topiaries. Finally, make sure you go and visit the Petit Trianon, which was Marie Antoinette's private escape from royal protocol. You'll also see her working farm and mini village that she developed and housed animals in near that area.
Pro Tip: This is an extremely popular tourist destination so make sure and get there early. We got there at about 8am and there was already a line outside the gate so pick your battle. There are also tour groups that allow groups to get in earlier if you'd like to book one of those.
2) Napoleon's Empress Josephine's Château Malmaison:
Château de Malmaison, is just west of Paris. It's also about 10 or so miles away from the city center (like Versailles) which could be a great reason to combine the two sites in one day. This is also equally as easy to get to from Paris. Just take the RER A(1) from Gare de Lyon and get off at Rueil-Malmaison. This is a special place because it was the former residence of Empress Joséphine de Beauharnais (Napoleon's first wife). It was also the headquarters for the French government from 1800 to 1802 and was the last residence of Emperor Napoleon in 1815.
Although not quite as grand as Versailles, it's still impressive. The caretakers have done an outstanding job of preserving the architecture and recreated some of the most authentic pieces of furniture to really let you see what it was like back in the early 19th century. Take time to explore the art and trinkets that were leftover from Josephine, Napoleon and their family. Afterward, spend some time walking around and marveling at the beautiful gardens and pond which house the famous 'black swans' of Malmaisson.
3) Giverny and Monet's Gardens:
Giverny is one of my favorite places in the world and it's another great day-trip just west of Paris. It's a village in the Normandy region of Northern France and is famous because the impressionist painter Claude Monet lived and painted at his home there from 1883 until his death in 1926. Again, very easy to get to at about 45 minutes by train. To get there by train start at the Saint-Lazar Paris train station (which looks about the same as when Monet painted it) and get off on the SNCF Grandes Lignes exit. If you'd like to rent a car in Giverny it would be better to get off at the previous station Mantes La Jolie which has car rentals. If not renting a car you can take a bus or taxi and go from there.
Once you get to Giverny spend time exploring the artist's former home (my favorite area is the kitchen with beautiful blue tile and display of French copper cookware). However, the biggest showstopper will certainly be his beautiful gardens which he painstakingly cultivated to relax and draw inspiration from. Most notable is the small pond which houses countless water lilies and was the inspiration for his most famous series. Although this will certainly be the most show-stopping area in Giverny, spend some time exploring the nearby Musée des impressionnismes, which highlights the Impressionist art movement. Finally, I have to say that there are a number of absolutely adorable French shops and cafes around this area which are great for shopping and a light lunch. If you have more time you might even consider staying at one of the several quaint bed and breakfasts in the area.
4) The town of Rouen:
Another great place to visit, and just north of Giverny, is the port-city town of Rouen, which is the capital of the Normandy region. Again, visiting Giverny and Rouen in one day may be possible if you're looking to fit a lot in. It was an important out-post during the Roman era and Middle ages which is reflected in it's Gothic churches and spires, cobblestoned city center and medieval half-timbered houses. What makes this city particularly famous is because this was where the military leader and Catholic saint, Joan of Arc was burned at the stake in 1431. In fact you'll see local confections called 'Joan of Arc tears' sold around the town as souvenirs. These are almonds dusted in cocoa powder and are actually incredibly delicious! Make sure to find the Gros Horloge (the great clock) which is a 14th century medieval, astronomical clock in the Renaissance arch crossing. Finally, make sure to check out the town's Cathédrale Notre-Dame, which was often painted by Monet. However, what's particularly special about this is the light show that happens each night. It was truly a magnificent surprise to see beloved French tales relived through projection mapping along the front of the church, definitely stay and see this!
5) Normandy (D-Day Beaches and Mont-Saint-Michel):
Normandy is the Northern region of France and it's truly beautiful. Think quaint sea-side village... It has a varied coastline that runs along the entirety of northern France and includes the famous WWII D-Day landing beaches of Omaha, Gold and Juno. Definitely make a day out of this and stop along the beaches and explore the D-Day museum and see how the artificial piers were built to create the ideal landing place for the allied forces. Beyond the historical significance, this is a great town to explore, shop and grab lunch. Afterward, if you can, head over the to American Cemetery in Normandy to honor those lives lost during the invasion. I'm sure some if not many of you have family that fought during WWII. Both of my grandfathers and great-uncles fought in the war. Unfortunately, one passed away on those beaches so I can't tell you how humbling and emotional it was to walk through and pay respects to those who made the ultimate sacrifice, truly beautiful.
Additionally, if you go just about an hour and a half south west you'll come to the heart-stoppingly, stupendous island of Mont-Saint Michel, with its soaring Gothic abbey. Historically, the island held fortifications during the 8th century and houses a monastery. What's particularly special about this island is that it's only accessible at low tide and becomes an island again at high tide. This is a UNESCO world heritage site and is one of France's most visible landmarks, housing over 60 buildings and business that still operate today. Both Normandy and Mont-Saint Michel are hard to access by public transport from Paris so it may be beneficial to book a tour that buses you around to both locations. Alternatively, you could rent a car and do the drive yourself and stay at a hotel in the the town of MSM itself!
6) Various Chateau's in the Loire Valley:
The last great day trip I would recommend would be to explore the famous Loire Valley, which is located in the middle stretch of the Loire River in central France and is another UNESCO World Heritage site. This valley is part of the architectural heritage of the historic towns of Amboise, Angers, Blois, Chinon, Montsoreau, Nantes, Orléans, Saumur, and Tours which run along the Loire River. As a whole, this area is comprised of 42 chateaux, many of which produce their own wine and illustrate the renaissance ideals of French design. You won't see all in one visit but here are my favorites: Chambord (the largest chateau), Chenonceau (once owned by Catherine de Medici), Villandry (stunning gardens), Ussé, Amboise, Cheverny, Le Clos-Luce (Leonardo da Vinci's home) and Blois. Again, I would recommend booking a bus tour or renting a car as this area is about 2 hours SW of Paris. You'll be heading to a lot of different locations and will want transportation. You can also stay in a chateaux overnight as well which would be beyond amazing!
These are just a few recommendations for getting out and about near Paris. I'd love to hear any other recommendations you may have!