Before you go: the route and the train
Three decisions shape this trip more than any single sight. Get them right and the route below runs like clockwork.
Fly ‘open-jaw’ (or round-trip)
Book an open-jaw ticket — into one city and out of the other — so you never backtrack. Flying into London and out of Paris is a natural default (London is the bigger long-haul hub). A round trip based on either city works too — the Eurostar runs both ways.
Take the Eurostar, book early
The Eurostar links St Pancras and Gare du Nord in 2h16 (city centre to city centre — beats flying door-to-door), ~16 trains a day. Fares start ~£39–52 one-way but climb past £150 walk-up, and booking opens 11 months ahead — reserve as soon as your dates are firm.
Allow for check-in & the EES border
It's an international train: arrive 60–90 minutesahead for ticket, security and UK & EU passport checks at St Pancras. Since April 2026 the EU's EES biometric registration (passport scan, photo, fingerprints — free) applies when you cross into the EU. And book the Louvre, Eiffel Tower and Tower of London timed slots ahead.
Days 1–4 · London
London: monarchy, world museums and markets
Start in London — sprawling, layered and English-speaking, an easy gateway to Europe. It's a city of royal history, world-class museums (most of them free), riverside walks and West End theatre, with the longer must-see list of the two, so give it four days. Base centrally and ride the Tube.
Getting there
Fly into a London airport — Heathrow (Elizabeth line, Piccadilly line, or the fast Heathrow Express) or Gatwick (Gatwick Express) — and tap in with a contactless card or an Oyster (a daily fare cap beats singles). St Pancras International, the Eurostar terminal, is central in King's Cross. Book the Tower of London and any timed sights before you arrive.
Royal & historic London
The set-piece capital: Westminster (Big Ben, the Houses of Parliament, Westminster Abbey), Buckingham Palace with the Changing of the Guard, and the Tower of London with the Crown Jewels (book a timed ticket). A day of a thousand years of English history in a walkable core.
The free world museums
London's best asset is world-class and free: the British Museum (the Rosetta Stone, the Parthenon marbles), the National Gallery, the V&A and the Natural History Museum, and Tate Modern on the South Bank. Permanent collections are free — only special exhibitions are ticketed — so museum-hop without a bill.
The South Bank, markets & the West End
Walk the Thames South Bank past the London Eye to Borough Market for lunch, browse Covent Garden and the East End markets, and cap a night with a West End show. This is the London to wander — free river walks and world theatre in equal measure.
Full details: the London guides
For a day-by-day plan of London — the free-museum routes, the timed-ticket rules, and the Tube fares — follow the dedicated 4-day London itinerary (and the free-things-in-London guide), then rejoin this route for the Eurostar to Paris.
London's national museums are free; the main paid sights are the Tower of London, the London Eye and the Churchill War Rooms — book those ahead. Use contactless or an Oyster on the Tube (the daily cap saves money over singles), and avoid the rush-hour crush where you can.
Days 5–7 · Paris (+ a day trip)
Paris: art, boulevards and café culture
Take the 2h16 Eurostar to a completely different rhythm. Paris is the city of art and the good life — grand museums, Haussmann boulevards, café terraces and the Seine — compact enough to walk. Three days cover the icons, with a spare fourth for the palace of Versailles.
Getting there
From St Pancras, the Eurostar reaches Paris Gare du Nord in about 2h16. Arrive 60–90 minutes before departure for check-in, security and the UK & EU border (including EES — see below); at Paris you simply step off the train. Gare du Nord is central, on the Métro and RER. Book your Louvre and Eiffel Tower timed slots before you travel.
The icons
The three everyone comes for: the Eiffel Tower (book timed lift tickets — they sell out), the Louvre (the Mona Lisa and miles of galleries; timed entry, closed Tuesdays), and Notre-Dame — reopened in December 2024 after the 2019 fire, free to enter but with timed slots to manage the queue.
Art & the Seine
The Musée d'Orsay holds the world's great Impressionist collection in a former railway station; from there, walk the Seine past the Île de la Cité and into the medieval Marais. Paris's centre is small, so the art and the river string together on foot.
Montmartre & a Versailles day trip
Climb to the hilltop village of Montmartre and the free Sacré-Cœur for the city view, and — with a spare day — take the RER out to the Palace of Versailles (about 45 minutes; book ahead, closed Mondays) for the Hall of Mirrors and the gardens. A grand finish to the trip.
Two closures to plan around: the Louvre is shut on Tuesdays and Versailles on Mondays. Book the Eiffel Tower and the Louvre timed slots ahead — the Eiffel lift in particular sells out — and use a Navigo Easy card or contactless on the Métro.
Getting between the cities
The Eurostar is the spine of the trip. Here is the route, the 2026 fares and border process, and the airport transfers at each end.
| Leg | Time & fare (2026) |
|---|---|
| London → Paris (Eurostar) | ~2h16, London St Pancras → Paris Gare du Nord, ~16 trains/day. From ~£39–52 one-way booked ahead (£78 return), £150+ walk-up. Booking opens 11 months ahead. |
| Check-in & border (EES) | Arrive 60–90 min before; gates close 30 min prior. Ticket + security + UK & EU passport control all at St Pancras before boarding (walk straight off in Paris). EES biometric registration applies from April 2026 — free, done at the station. |
| London airports → centre | Heathrow: Elizabeth line (~£12) / Piccadilly line / Heathrow Express (15 min). Gatwick: Gatwick Express (30 min). St Pancras is the Eurostar terminal. |
| Paris airports → centre | Charles de Gaulle (CDG): RER B ~€11.80, ~35 min, or the Roissybus. Orly: Orlyval + RER, or the tram. Gare du Nord is central. |
| City transport | London: contactless/Oyster on the Tube (daily fare cap). Paris: Navigo Easy or contactless on the Métro (t+ tickets / carnet). |
The other quiet upgrade is context. A British Museum gallery or a Louvre wing you understand is one you remember — so before the Rosetta Stone or the Mona Lisa, it helps to have the story in your ears rather than reading a label in a crowd.
Plan it with HipiMind
Plan this trip by talking
A two-city trip with an international train in the middle and a menu of day trips is exactly where a planner earns its keep. That is what HipiMind is built for. It is a voice-first AI travel assistant: describe your trip out loud — “a week in London and Paris, we love history and art” — and it turns the conversation into a day-by-day itinerary with every stop and the Eurostar leg placed on a map. Because it maps the whole route, you can see how many days each city really needs, where the Louvre, Eiffel Tower and Tower of London timed slots fit, and how the Eurostar check-in and EES border timing work — and fix the plan before you book.
For each city, ask HipiMind to generate a long-form audio guide — the story of the Tower, the meaning of the Impressionists, the making of royal Paris — and listen hands-free as you walk. It is interruptible: pause to ask a question, get an answer, and resume where you left off. It plans and narrates in the language you speak, across 32 languages, right in the browser — no app to install.
The free tier includes 3 voice sessions and 1 audio guide per calendar month. HipiMind Plus is $7.99/month ($59/year) with 60 voice sessions, 20 audio guides, and full trip memory across journeys. HipiMind plans and narrates — it does not book flights, trains, hotels, or timed-entry tickets, and it is not a GPS-triggered on-site tour; confirm times, fares, and reservations with the provider.
London & Paris itinerary FAQ
How many days do I need for London and Paris?
A week is the sweet spot — about four days in London and three in Paris. London has the longer must-see list (the royal sights, the free world museums, the markets and the West End), so it earns the extra day; Paris's compact centre and its icons fit comfortably into three, with a spare day for Versailles. You can split evenly (3–4 each) if you prefer, but fewer than three days in either capital means missing its character. With ten days you could add day trips — Windsor or Oxford from London, Versailles or Giverny from Paris.
How do I get from London to Paris?
Take the Eurostar — the only through train via the Channel Tunnel, and the best option by far. It links London St Pancras International and Paris Gare du Nord in about 2 hours 16 minutes, with roughly 16 trains a day, seven days a week. Fares start around £39–52 one-way (£78 return) in Standard when booked ahead; walk-up fares can be £150 or more, so book early — reservations open up to 11 months in advance. It runs city centre to city centre, so it beats flying door-to-door.
Should I take the Eurostar or fly between London and Paris?
Take the Eurostar. Although a flight is about 1h15 in the air, the door-to-door time is 3–4 hours once you add getting to and from two airports, security and boarding — versus the train's 2h16 straight into each city centre. The Eurostar is more comfortable, more frequent, more reliable, and it drops you in the heart of each capital (St Pancras in central London, Gare du Nord in central Paris). Flying only makes sense if it connects directly to a long-haul flight.
What is the check-in and border process on the Eurostar in 2026 (EES)?
The Eurostar is an international service, so allow time: arrive 60–90 minutes before departure (the recommended time is on your ticket; gates close 30 minutes before). Ticket checks, security and both UK and EU passport control all happen at St Pancras before you board — which is why you can simply step off the train in Paris. Since 10 April 2026, the EU's Entry/Exit System (EES) is fully live: crossing into the Schengen area, non-EU travellers (including British citizens) register biometrics — a passport scan, a photo and fingerprints. It's free, needs no advance application, and is done at St Pancras (kiosks and border control) before you leave the UK; after your first registration it's quicker. You'll also complete Advance Passenger Information (API) when you book. ETIAS — the EU's separate €20 pre-travel authorisation — is expected but was not yet in force in 2026; when it launches, apply only on the official EU website (beware of fraudulent ETIAS sites).
Which order should I visit — London or Paris first, round trip or open-jaw?
Either order works, so let your flights decide. An 'open-jaw' ticket — into one city and out of the other — means you never backtrack: fly into London, take the Eurostar to Paris, and fly home from Paris (or the reverse). A round trip based on either city works too, since the Eurostar links the two centres directly in both directions. London is the more common long-haul entry point for travellers from North America and Asia, which makes London-first a natural default.
What day trips can I add to a London–Paris trip?
Plenty, at both ends. From London: Windsor Castle (about 30 minutes by train), the university city of Oxford, Georgian Bath, Stonehenge, or the Warner Bros. Harry Potter studio tour. From Paris: the Palace of Versailles (RER C, about 45 minutes, closed Mondays), Monet's garden at Giverny, the Champagne city of Reims by high-speed train, or Disneyland Paris. Any of these turns a spare day into a highlight — Versailles is the classic add-on to the Paris leg.
How can HipiMind help me plan a London–Paris trip?
A two-city trip with an international train in the middle and a menu of day trips is exactly where an AI planner earns its keep. HipiMind is a voice-first AI travel assistant: describe your trip out loud — 'a week in London and Paris, we love history and art' — and it turns the conversation into a day-by-day itinerary with every stop and the Eurostar leg placed on a map. Because it maps the whole route, you can see how many days each city really needs, where the Louvre, Eiffel Tower and Tower of London timed slots fit, and how the Eurostar check-in and EES border timing work — and fix the plan before you book. It can also generate long-form audio guides for each city. It plans and narrates but does not book trains or tickets, so reserve your Eurostar seat and timed entries yourself, early.
Sources
Train times, fares, the check-in and EES border process, and opening rules in this guide were grounded in the following official and authoritative sources (checked August 2026). Fares, border rules and museum days change — verify before you travel.
- Eurostar — official London–Paris booking, fares & check-in times
- Seat61 — London to Paris by Eurostar (authoritative rail guide)
- GOV.UK — the EU Entry/Exit System (EES), official guidance
- visitlondon.com — official London tourism (sights & transport)
- Paris je t'aime — official Paris tourism (sights & day trips)