One & 1/2 days in London

Assuming your flight arrives as scheduled...by the time you get through customs, make your way into London proper and drop your bags at your hotel, it will be late morning, and then you'll have to head to the airport early the next afternoon (lines at baggage drop and security can get long in my experience). So you're really looking at a little over 24 hours. You need to do the math and figure out if the London Pass or the hop-on/hop-off bus is worth it given what you want to see (also, the British Museum is free so take that out of the equation).

The other thing is that London is vast and none of the sites you listed are really near each other. You may be better served by taking the tube as you're likely to be stuck in traffic on a bus.

With your limited time it makes no sense to stay at the airport. I would try to find a hotel on the Circle/District tube lines, which are convenient to the Churchill War Rooms, St. Paul's and the Tower among other things, and go from there.

Way too much you want to see -

Pick one place , max two .

My teens enjoyed the beefeaters Tour at the Tower of London - and the British museum .

The Churchill War Rooms are quite expensive if you only want to see the war rooms themselves and ignore the Churchill Museum. If you want a full visit, it can easily take half a day or longer. To avoid a potentially very long ticket-purchase line (and conceivably a sell-out), you must buy timed tickets in advance. This will not work well with your limited time. You can't be sure when you'll get out of LHR, into the city, drop your bags off and finally get to your first sightseeing stop. Although this is a quality historical site, I would not try to squeeze it into your very tight schedule.

The British Museum is a monster. It takes multiple visits totaling multiple full days to see the whole thing. The best you can do is look at the website ahead of time and select a very few areas to prioritize. The ground floor tends to be extremely crowded, including the highly popular Egyptian section. You have to go through a security line to enter the museum (possibly faster if you arrive with no purse, bag, etc., but I'm not positive about that). I've stood in that line for more than 30 minutes on several occasions, so check immediately to see whether you can get a timed entry online that works with your schedule. You really cannot afford to spend much time waiting in line.

I've not been inside St. Paul's and visited the Tower of London a very long time ago, so I have no comment on the time you're likely to want to spend there, but the Tower of London would normally be a significantly longer visit.

I must warn you that $150 (which is just £111) is a very low nightly hotel budget when you need space for four people. You'll need to select carefully to avoid places with really low reviews and/or inconvenient locations. If you stay very far from the center of town, you'll burn precious time commuting back and forth to sights (you'll be doing that four times within about 24 hours), and Underground fares are not cheap. A look at booking.com will give you an idea of costs. Booking directly is often somewhat less expensive.

Premier Inn hotels are often recommended, and they are typically very reliable. You can check their room rates on premierinn.com. Be very careful about the type of reservation you book; the lowest rates are not changeable or refundable. Flexible rates will cost substantially more. Up to two kids eat breakfast free with an adult paying for a full (not continental) breakfast, but the kids must be under 16.

"I noticed St Paul is closed on Sunday"

It's not open for tourism because it's Sunday, but its open and you can of course attend a service.

I think re budget that Premier Inn is a good option, but you're really likely to looking at two rooms, given your kids are likely to be classed as adults. I would suggest a budget of £150-£200 a night per room for budget level central London hotels, but there are some Premier Inn options in less central but still reasonable parts of London are bit below that. One that comes to mind is Clapham - not so close but not miles away either. Alternatively look at one of the many small budget places around Kings Cross and Paddington station, but ne away rooms are tiny.

Have you bought a multi city ticket for your flights i.e. home-LHR-Paris-Home? If not, and that is indicated given you are planning to change the flight to Paris, then it is a lot easier to take the Eurostar to Paris. The train leaves from St Pancras in central London and will deliver you to the Great du Nord in central Paris. That would save schlepping back out to LHR and in from CDG and the need to be at LHR 2 hours before the flight. But book that train now, it will only get more expensive.

I would really counsel against a HOHO bus service. The buses routinely get stuck in London's traffic and if you get off anywhere it can be difficult and slow to get back on another. In any case you really have no time to waste on sitting in traffic.

Good news, you will pick up one hour with time change on Sunday Oct 24.
Bad news, sunset is 5:30 on Saturday.
Recommend being weather flexible for alternate sites dependent on rain.
Stay in a premiere inn for good value and good rooms. Your budget of $150 is not realistic.
Suggest using google hotels London to explore options using their filters. Pay more to stay central to your London experience, your time is the most precious commodity. Most likely you will need to drop your luggage at the hotel and then have access to your room later in the day.
Let’s say you clear the airport by 10 and then take the underground to your hotel to drop luggage by 11. Note: I am rounding out time estimates to provide a guideline. You now have approximately six hours of daylight to enjoy a couple of sites. Walking is a great way to enjoy London, using the underground or taking the bus is superb for point to point. I am not a fan of HOHO buses, especially in London where the regular buses offer great views in getting you from point to point. Another excellent experience is to walk along the Thames and take one of water taxis to enjoy a travel mode utilized for over a thousand years, if you go to the Tower of London this is a convenient add on experience.
It’s now evening and dark and you have the opportunity to enjoy a great London experience, attending a play or musical. This is a great way to spend an evening at great value. Do some research on what’s available to attend and then learn how to purchase inexpensive tickets.
Flying out on Sunday at four consumes a big quantity of time. We prefer the underground for getting to Heathrow and allow 90 minutes for the trip. You will need to allow three hours for clearing through the airport. So advise heading to airport by 11 a.m. and no later than noon. Keep in mind you gain an hour with the time change. FYI: you will be arriving in Paris at very dark:thirty.
All in all your Sunday morning most likely allows time for only one site or event.

Thank you everyone with such great info! However, let me clarify our flt info. We do have multi-city flights which are the following:

London/LHR Sunday Oct26 arrive @ 8am and return to US, Thursday Nov6 from Rome/FCO at 11am. Our entire trip is to spend 11 full days in London, Normandy, Paris, Venice, Florence and Rome. Also , we already purchased flt tkts LHR/CDG for Monday Oct27th @4pm plan to drive to Normandy, once we arrive in Paris and stay a couple of nights/visit D-say and Mt St Michel) sites. We'll drive back to Paris, spend a night or two then fly CDG/Venice and figure out the rest in Italy. Our emphasis is WWll sites, with the typical landmark sites too. If we should keep to two sites in London, should we then stay close to Westminster abbey area, and as most mentioned skip the London pass?

Be aware that every time you change locations, you will lose at least 1/2 day. You have allowed less than 2 days/location and a significant amount of your 11 days will be spent on trains/driving. Maybe you like to travel this way, but your pace would have worn me out when I was in my 40's. Be aware that you cannot travel as efficiently as those on the group tours that go to a different city every day. You need to build some margin into your schedule-maybe only go to two cities in Italy. I agree with Pat about the top two sights in London for your teens. As you know, the British Museum is the world's attic with so many important items. I can't imagine taking teens to London if it's the first time they've been there, and not seeing a castle.

I think you're trying to do way, way, way too much in 11 days. Six cities in 11 days? I'd cut it down to two. London and Paris. Three tops, London, Paris, Normandy.

As it is, you won't have nearly enough time in London to see the things you've listed. Get with your kids and find out which 2 are most important to them. I'd suggest the Tower of London for sure. Don't bother with a hop on hop off bus. Complete waste of time. Use the tube to get where you want to go.

Since you'll be coming off the transatlantic flight, the common wisdom is to focus on getting outside and walking during your limited daylight hours, trying to stay awake as late as possible to adjust to the time change. But for me, a highlight of being in London on Sunday is a roast lunch. (Come at me, jet laggers). This is a cultural experience for your teens and, IMO, a GREAT way to kick off your family sprint through Europe. Reservations are a good idea. I used this list and was able to get in to William IV in Hoxton, which was very good. We took the bus there from Victoria Station. https://www.timeout.com/london/food-and-drink/londons-best-sunday-lunches

Since you're focusing on WWII, maybe book an early entry at the Churchill War Rooms as your sightseeing activity and leave the rest for next time.
There is a public bus (#12? 14? I don't know) that goes over Tower Bridge and back across Westminster(?) Bridge that is a relatively inexpensive way to get a glimpse of a lot of the marquee sights.
As others have noted, $150/night for a double room is on the very low end, and I'd be shocked if you were able to find a suitable room for your family for anything like that. I'd want to make sure I was in an area that will be fairly lively on Sunday evening. I don't know the city well enough to suggest an area.

Others may disagree but I would not say you need to be at Heathrow three hours early. I never arrive more than two hours early and it's absolutely plenty of time to drop bags (if you need to) and get through security. I travel through this airport regularly.

In terms of what to do, I'd say just pick one big attraction for the afternoon of your first day and another big one for the morning of your second day. You just need to prioritise what you want to do most.

There is a public bus (#12? 14? I don't know) that goes over Tower Bridge and back across Westminster(?) Bridge that is a relatively inexpensive way to get a glimpse of a lot of the marquee sights.

That's a distant (pre 2019) and fond memory. It was the RV1 Covent Garden to the Tower of London, and came back over Waterloo Bridge. Both buses that now go over Tower Bridge go to South East London. You'd have to change at the Bricklayers Arms now to come back on yourself.. But the bus 11 links the War Rooms and St Paul's then the 15 takes you to the Tower of London.
Various buses come down from the British Museum to the Strand to link with the 11 and the 15, but you can walk to Trafalgar Square for those as well through Covent Garden and continue down Whitehall to the War Rooms.

Emphasis on WWII…….
Churchill war rooms is a must. Highly recommend pre book tickets for specific timed entry to insure no glitches. Yes, you probably could walk up and purchase tickets, but every minute counts.
As a bad weather potential I recommend the Victoria & Albert museum with the natural history museum across the street. A bit of something for everyone. On the exterior white walls of the v&a you can find bomb damage deliberately left as a reminder of wwii.
Check out London Walks for excellent variety of guided tours and reach out to learn what they may offer of WWII focus.
If you go into St. Paul’s make a mental note of how much effort went into daily protecting the landmark during the blitz. If you can, be sure and climb to the upper floors to gain additional perspective.
If you attend the Tower of London politely approach a warden to inquire of their knowledge of how the place was protected during WWII, fascinating stories if they have time to engage.

Google Google Google London blitz history to learn of the many locations offering off the beaten path involvement w WWII.

Thank you everyone, I think I will cut London to stay in West London!

" I think I will cut London to stay in West London!"

Can you clarify what you mean? West London is in London... Your biggest challenge is your budget - i would suggest looking at South London for something more affordable, but it will still be tight.

@CatVH - agreed, 2hrs prior is plenty of time for Heathrow. I always arrive 2hrs prior and still have plenty of time for a coffee.

Hi! What a fun family trip! You have to first ask yourself and family this. Is this a trip OR a vacation? Vacations to me are more relaxing and trips are go go go! I like both options! I would consider taking the tube everywhere you want to go. Buses are fun and you can see things BUT if you are wanting to cram in a lot of sites, the traffic will kill you on time! Maybe ask the teenagers if they are more interested in riding the bus to see the London sites on a double decker or would they prefer to be able to see more of London overall cause the tube will help get you there quicker! Consider seeing sites that you don't necessarily have to go inside to enjoy like the Tower Bridge, Buckingam palace, Big Ben, Trafalgar Square etc. If you want to go inside some places, it depends on what your family enjoys. Westminster Abbey was one of my faves because it is beautiful and has grave sites of some of the most famous people in history! It also doesn't take a lot of time to walk through honestly and you have Big Ben and the London Eye right there too. St James is the same, not a lot of time is needed in my opinion to enjoy it. Tower or London will take up a bit of time, but is completely doable. Definitely get a Beefeater tour to help you see the good stuff! I agree with my fellow travelers with the British Museum. Saying there is a lot to see is an understatement. But don't let this deter you! If this is a must, definitely map out the exhibits you want to see because it is easy to get turned around and side tracked. I would say get a hotel close to the airport so you don't have to worry about much of a commute. We are staying at the Premier Inn and have heard it is good for a one night stay and right by the airport. I think it is within your budget as well. Don't do air BNB in my opinion because a lot of them have cleaning lists that you have to strip beds and wash dishes etc and that will just cut into your exploration time! Good luck and have a great time!

It does depend on what you mean by ‘west London’ but be aware many of the more expensive areas of the city are in the west. If your budget really is tight Simon’s suggestion to look south is a good one.

I wrote West London, meaning closer to airport but guess I need to get better on my geography lol! So I reserved a $250 hotel 10 min walking distance to Bristish museum. Thank you so much to all for all your insight.

Hello! For what it's worth, the Tower of London was one of my teenager's top highlights from our 11 day UK trip! So I would highly consider allowing a lot of time for that if you can. We were there for about 4 hours, though you can do it in less time of course.

Churchill War Rooms were very interesting as well. We booked the first entry and were done by about 12pm.

British Museum is wonderful but TBH I'd skip it for this trip unless there is something very specific they want to see. Only because I think your teenagers may be more engaged elsewhere.

For an inexpensive hotel, maybe consider Premier Inn by Paddington Station. You can take the Heathrow Express to and from there which should be quite easy!