Don't get lulled into thinking two 15 minute train rides in/out of London equals half an hour round trip. There is a bit of wait for the next train at both ends - plus long walks at the LHR end, shorter at the Paddington end. So count on the roundtrip transfer being anything up to an hour.

And do not discount how unwieldy a double stroller will be at LHR and Paddington, on the train, on a bus, or in a taxi.

Have any of your kids flown overnight before? It may hit them a lot more than you think. Which terminal(s) are you using at LHR?

Lulled?

HX trains run every 15 minutes. Average queuing time for two trains is therefore 15 minutes. Yeah, that's going to cut deeply into your four hours.

My view isn't about timing and whether it is possible or adviseable... it's about exhaustion! The last thing I'd want to go between two long flights (myself let alone with 3 small kids) is make a mad dash around London.

I think a day room sounds perfect, maybe there's a gym or pool or activity room. Have showers and a short nap. Plus you'll want to have a decent meal in that time.

The big question is, where are you flying from in the States? if its the East coast you shouldn't be THAT tired, despite the three little ones, who lets face it, WILL fit on the seats, curl up nicely and probably sleep better than you do. Yes you will be a little tired, but then you are getting back on a long flight and you will be able to sleep again when you get back on. However if you are coming from the west coast or somewhere in between, then I probably agree with the others, grab and room and have a sleep.

Thanks again for the tips. We will be coming from Washington DC so the trip should take around 7.5 hours and we'll be ariving at Terminal 3. Our following flight will be from terminal 4 on British to Alexandria, Egypt and should take around 4 hours. The last thing we want to do is to wait inside the terminal as we've been in a similar situation last summer at Frankfurt airport and it was quite hard trying to keep the kids entertained and controlled for 6 hours while waiting for our flight. An airport hotel could be a very good idea but I'm still tempted to take the small adventure and visit London.

If you opt for Windsor rather than London, you can go by city bus directly from the airport in about 30 minutes. Or you can take a taxi.

I will join others in recommending that you skip trying to see London ... last time I went thru London ... US to London to Waterloo for a train to Paris. We went through customs and immigration and immediately to the tube station for the Waterloo trip ... plane landed at 8:30 AM. When we arrived at Waterloo, it was nearly noon. We did have to pick up luggage, but that didn't take too long.

Why not relax, have a snack and enjoy some duty free shopping?

Dear JNetter, I used to live in Maryland and would fly out of Philly or DC all the time, so I know the flight well, you will be fine. Go, have fun, yes you could be a bit stressed, but hell I have a kid and frankly you are more likely to have your head implode if you stay in the airport and try to keep them entertained. Go and wear them out. Live is short, you may never get the chance again.

You sound like seasoned travelers, but as someone who has traveled a lot with young children also I've got to say that I think you'd be nuts to do this. I speak from good experience. I flew to London with my two small children (ages 2 & 6) in February (we're still here) and cannot imagine trekking all the way to London for a couple of hours having just flown across the Atlantic, and then facing another long journey. No way! That sounds so nuts to me! I get the need to find a place for the kids to run around, get some energy out, but an excursion into London would require some more sitting still time on the train/tube and overall that just sounds miserable to me. Plus I really think you'd be constantly checking your watch the short time you'd have in London, which would really take the fun out of it for me. If you are insane enough to do this, head to Westminster Bridge, see Big Ben & Houses of Parliament, ride the Eye and there is a playground right behind the Eye so the kids can get the wiggles out. There's also places around there to grab a quick bite and souvenit stalls for those must-have "we went to London" souvenirs. I still say don't do it, but that's what I would do if you did.

I've never done it but maybe you could hire a guide to meet you at LHR & take you for a brief tour. If you're arriving on a Sunday the traffic isn't as horrendous & the driver would return you to the airport. This is one I found online to give you an idea:

http://tinyurl.com/s98qd