07:00 - 10:00 – Getting to Paris Gare du Nord

If you're really keen to get to Paris, the first Eurostar train leaves London St Pancras International for Paris Gare du Nord at 05:40. However, if you want to give yourself a few more winks, consider getting to St Pancras just after 06:00 and taking the 07:01 service. It's half an hour faster (2h 16m instead of 2h 36m) and gets you to Paris at 10:17, only an hour after the earlier train.

There's no baggage check-in to worry about, no luggage weight limit, and no limit for liquids to carry onboard. And if you miss out on breakfast at home or the station, you can buy snacks and breakfast on the train. Alternatively, if you opt for a premier travel class ticket, a meal is included. Most trains have WiFi and charging sockets, too – perfect if you've left your phone unplugged overnight.

10:00 - 11:30 – Explore the 10th Arrondissement and St Quentin Market

The Eurostar arrives at Paris Gare du Nord, in the 10th arrondissement of Paris, where there's plenty to see and do. The 19th-century town hall is the most monumental (and expensive) of Paris's many mairies. Covered in colonnades and spires in over-the-top Renaissance style, Saint-Vincent de Paul is architecturally unusual for a church, with massive Roman columns and a neo-classical facade. The Canal Saint-Martin runs through here before disappearing underground and re-emerging near Place de la Bastille. Get ready to do your best Amélie Poulain impersonation, skimming stones along the shop-and-café-lined quays.

St Quentin Covered Market is just 10 minutes' walk from Gare du Nord. Browse the many wonderful fishmongers, butchers, and fresh produce stalls here while vendors yell above the buzz of the crowd. It's a true Parisian experience. There's also a great bistro at the edge of the market where you can pick up a coffee, croissant, or something more substantial.

11:30 - 13:30 – Notre-Dame Cathedral and the Latin Quarter

Wander back to Gare du Nord and hop on the RER B train to Saint-Michel Notre-Dame for 7-10 minutes. Walk two minutes, and you'll be at the gargoyle-covered cathedral that inspired Victor Hugo's famous tale. Instead of queuing, cross the little bridge in front of Notre Dame, over to the left bank of the Seine.

Square René Viviani, 200m from Notre Dame straight across the river, is the best place to view the cathedral in all its glory. Taste a famous choux pastry puff from Odette, an iconic bakery on the corner of the square, before wandering into the medieval Latin Quarter. See the neighbourhood's countless bookshops, including famous Shakespeare & Company. The Paris Pantheon and Sorbonne University are also here, as are the Luxembourg Gardens and Garden of Plants, perfect for a stroll in the fresh air.

13:30 - 17:30 – Lunch at Place Monge and the Musée d'Orsay

By this stage, you'll be getting pretty hungry. But no need to worry, as you should now be close to Place Monge, in the heart of the Latin Quarter. The area is full of brilliant bistros and affordable student eateries. For a quick bite, Au P'tit Grec does the best crêpes in the neighbourhood, and possibly the city. Or squeeze in at popular La Montagne Sans Geneviève, a favourite bistro among students and locals and away from the crowds.

After lunch, take the metro from Place Monge to Palais Royal Musée du Louvre. The Louvre Museum is a must-see for all art lovers. However, as it's the world's biggest art museum, with 38,000 artworks across 800,000 square feet, it's impossible to see in just a few hours. Instead, admire the Louvre's iconic (and divisive) glass pyramid, the magnificent palace, and the Tuileries Garden on your way across the river towards the Musée d'Orsay. These sites are more manageable than the Louvre during a day trip from London to Paris, but no less impressive. Focusing exclusively on 19th- and early 20th-century European art, it has the world's best collection of impressionist paintings by Monet, Van Gogh, Gauguin, Cézanne, Matisse, and many more.

17:30 - 20:30 – Sacré-Coeur and Montmartre

At this point, you have two options. You could take the metro to the Arc de Triomphe and then the Eiffel Tower to make it back to the Gare du Nord in plenty of time for the last train back to London at 21:13, and back to St Pancras just before midnight. Alternatively, you could head to Montmartre.

From Assemblée Nationale, five minutes from Musée d'Orsay, the metro takes 25 minutes to Abbesses in Montmartre. From there, it's a 10-minute walk to Sacré-Coeur. Overlooking Paris from the top of a hill, this famous Basilica is a fantastic place to watch the sunset. There are also quaint restaurants, trendy bars, and the famous Moulin Rouge nearby, so it's no secret that Montmartre is one of Paris's best places to be as the sun goes down. And it's only a 20-minute walk or 10-minute train to Gare du Nord for the train back to London.

There you have it – how to pack in a full day of sightseeing, relaxing, eating, and drinking in Paris without spending a night outside London. But there are plenty of other ways to do it. Have a look through different train times, destinations, and things to do in Paris to make your own itinerary!