Day trip to London from Paris

Picadilly Circus, Trafalgar Square, Parliament, St.Paul Cathedral, Buckingham Palace and you can go and go. There are simply so many more "must sees" than you can see in such a short time. You can use hop on hop off bus. And a lot of walking.

The HoHo's are expensive tour buses and shouldn't be considered as normal transport, better to use the public transport to get to places.

If you take a taxi to Trafalgar Square, you can walk to Buckingham Palace, past the Horse Guards Parade ground and the mounted British soldier, Parliament, Westminster Abbey, cross the Thames to the London Eye, even walk down to Tower Bridge. The National Gallery and the National Portrait Gallery are adjacent to Trafalgar Square. Check out Saint -Martin-in-the-Fields church and its Cafe in the Crypts for good food and a place to sit and enjoy a cold drink. We used the HOHO bus on our first trip but it was caught up in traffic and we could have spent more time walking once we got to Trafalgar Square.

Sorry, a day trip to London from Paris is an inefficient use of time. Further, the cost of the RT train trip outweighs the modest amount of time you will have in London.

How long will this day trip be exactly? If you arrive on the first train of the day and leave on the last one, it looks like that gives you about 11 1/2 hours in London (or closer to 10 1/2 when you account for the time you need to check in at St. Pancras for your trip back to Paris). Is that what you're doing, or will your day be shorter than that?

London is a big city, and the "sights" are pretty spread out. A bus tour (HOHO or otherwise) will give you a glimpse of the main ones, but as mentioned, because of traffic, it can take a long time. A more efficient use of time might be to decide where you want to go and then get there yourself on the Underground.

What kinds of things are you interested in? (Art, architecture, history, royalty, churches, markets...?) A lot of the standard "must sees" are things I've never been remotely interested in, and the same may be true for you. If so, that could help narrow down your itinerary.

If you have time to fit in a visit to a museum, you could do worse than the Museum of London, which tells the basic story of the city you're visiting.

Thank you so much for all the input. We are taking the early train into London and latest train back to Paris. Truthfully, I'm not too sure what I want to see, I just want to make good use of my 10 hours. We definately want to see all the "big" and most popular landmarks and I'm hoping to see one museum. This will be my first time seeing London and my husband's 2nd time.

If you have not been there before, I might suggest the tube to from St. Pancras to Leicester Square. This will put you near the National Gallery/National Portrait Gallery (both of which are free) and Trafalgar Square. You can walk down Whitehall to the Houses of Parliament, Big Ben and Westminster Abbey. The Churchill War Rooms, Downing Street and the House Guards Parade is also along this route. You can walk through St. James Park to Buckingham Palace if you want to see the changing of the guard there. Or you can take a river cruise (or the tube) from Westminster down to the Tower of London and Tower Bridge.

You have to book a tour of Houses of Parliament in advance, though not the case for Westminster Abbey. Buckingham Palace will likely also be open for tours in August. Both of these tours will probably take out 2 hours of your day, FYI, and neither of them are particularly cheap.

Alternatively, St. Pancras itself is not far from the British Museum.

Lastly, I think it's ultimately how adventurous you want to be and how fast/slow you like to tour things. The tube is an easy way to get around - and will get you places faster than HoHo buses - and London buses for shorter distances.

I think georgia's suggested plan is really good. You can go inside places like Westminster Abbey, or just view them from the outside, depending on how fast or slow you want to go. A visit to the Tower of London that really does it justice would probably take more time than you have, but it's up to you.

The only think I'd add might be a visit to Harrods or one of the other iconic London department stores (e.g., Selfridges, Fortnum & Mason, Liberty...) Unfortunately, they're not very close to one another, and none of them is especially close to anywhere else you're going to be. So pick the one that interests you most and head there on the tube once you're done with everything else.

The post above is exactly what we are all talking about when we say you have to decide on your own what your own "must sees" are. If I had only a day in London (or anywhere else), the last place I'd go would be a department store. (That said, Liberty is indeed unusual, or at least it was at Christmastime 1985 when I went).

For Rick's list of London's highlights, scroll down and click on "At A Glance": https://www.ricksteves.com/europe/england/london.

First, I think it would be smart to purchase the Rick Steves Pocket Guide to London. Here, from the RS website shop. $12.99 and it includes a fold-out map.
https://store.ricksteves.com/shop/p/pocket-london
This will give you a good overview. It is not the full-size heavy guidebook that others buy who will be in London for a week.

Second, I must agree with Harold. If I only had 10 hours in London, I would not go to a department store!

There are so many things to see in London, I hardly know where to begin.

For a quick overview, nothing beats a ride on the Hop-On-Hop-Off bus. There is one called the Original Tour. They have three different routes around London. When you purchase your ticket, all three routes are included. Ride them all.

Your ticket includes a riverboat ride on the Thames River. You can get on at Westminster Bridge, near Big Ben and Parliament, and ride to the Tower of London. You get a good look at some of the sights from the river.

Many people are saying to take a walk around, and that's great. But you won't cover much ground that way. The HOHO bus gets you around the city fairly quickly. You will get a glimpse of all the landmarks. You could never see it all just walking.

Some sights are only worth a drive by if you are in a hurry. Piccadilly Circus and Trafalgar Square--you can see these plenty well from the bus.

Normally, these HOHO buses are not used for transportation. For regular transportation most people ride the tube or the city bus.

The HOHO is a tour bus, and it's purpose is to give you a drive-by of the famous sights, which is what you want. (However, do make use of its hop off hop on function. You can get off, see a sight, hop back on.)

The HOHO bus ticket is good for 24 hours. We know you won't be there that long, but it's nice to know it won't expire if you get off at a must-see sight, and then want to get back on the HOHO bus afterwards.

I find the best use of the HOHO bus is to stay on each route (remember there are 3 routes) until the loop is complete. Stay on to go back to a sight you want to see.

If you do the HOHO rides early in the day, the second half of the day can be spent at a couple of sights and a museum or two, plus a couple of walks as described by other posters.

Many people like the Original Tour best, choosing a bus with live commentary by a guide.
https://www.londontoolkit.com//whattodo/london_hoho_bus_discuss.html

Make a list of sights you want to want to go inside and spend some time looking around.
Tower of London?
Westminster Abbey?
St Paul's Cathedral?
British Museum?

Reading the Rick Steves Pocket London book will help you decide which are your own personal "must sees".

When one of the posters above asked you what your interests were, you replied,
"Truthfully, I'm not too sure what I want to see, I just want to make good use of my 10 hours. We definately want to see all the "big" and most popular landmarks and I'm hoping to see one museum. This will be my first time seeing London and my husband's 2nd time."

--To see all the big and most popular landmarks, you will only be able to glimpse them all with HOHO bus.
As others have said, you can do a walk around say, Westminster to see the sights. But then it's a long walk to Tower of London and Tower Bridge. Can be very time-consuming.

--You are hoping to see one museum.
It will help you to know what's in each museum, so you can choose.
The Rick Steves pocket guidebook will help here.

For paintings--a number of museums.
For artifacts from different civilizations and time periods, the British Museum.
For a variety, the V&A--Victoria and Albert. Costumes, furniture, some paintings, silver.
For the history of London--The Museum of London.

What museum you choose depends on what you want to see. What your personal interests are.
The British Museum would be my pick. Or V&A.

I'd go with Georgia suggestion but I do it this way. Take the Underground from St Pancras/Kings Cross to Westminster Station. Blue Victoria Line to Green Park, Mind the Gap, change trains and take the Grey Jubilee Line to Westminster. 20-25 minutes total.

Exit at Westminster and you will know you are in London as the iconic Elizabeth Tower which houses the bell Big Ben is what you'll see in front of you.

After looking at the exteriors of Parliament, Westminster Abby and maybe the London Eye across the Thames from Westminster Bridge you could the see the Churchhill war rooms or the interior of the abbey depending on your interest and crowds. You will probably miss the Changing of the Guard which IMHO isn't worth waiting around for anyway especially with your constructed time frame. However by walking up Birdcage Walk from Parliament square you will se St James Park, the Victoria Memorial and the Palace.

From here walk back down the Mall to Whitehall and up to Trafalgar Square, The free National Gallery. Have lunch in the Crypt of St Martin's of the field or over to Covent Garden and eat there.

If truly interested in something like Harrods or the British Museum or????
Use the tube to get close and walk.

Take a moment to use the Google Maps satellite view to see how close or far the iconic sites are....type in Big Ben London and go from there.

Great city. Enjoy your brief visit.

What a great response! I have a lot to go from and think about! Thank you for the time and effort to help me with my day in London. I'm so excited! I do plan to look at the Steve Rick's book when my friend is done with her trip this spring.

I would suggest that you pick your two "must see" sights and work your itinerary around them. Plan one sight for the morning and one sight for the afternoon. Add a lunch in an interesting place (could be a pub lunch, could be a takeaway sandwich in a park). Then, figure out what else can me worked in.

Personally, I'm not a fan of HOHO buses in any city. While they do give you an overview, I always feel it is a rather mediocre experience. On day trips, I prefer to focus on a couple key sights, spend some time enjoying a walk through an interesting part of the city, and enjoying a nice lunch.

Take the tube (underground), it's quick and easy and covers all of London.
I'd recommend visiting as many Museums as you can fit in one day. I really like the British Museum and Science Museum, bot are easily accessible by the tube.