Day trip to Paris from London

Rick's London guidebook has an entire chapter dedicated to doing the Chunnel train day trip to Paris efficiently. You can order the book edition at this website, or the Kindle edition over at amazon.com

What time of year? What do you want to see in London? The Eurostar does get delayed, so you have to be comfortable with not arriving exactly on time. And because it's international travel, you have to check in early for passport control, and can't just show up at 8:00 to catch the 8:01 train. Which means you could have as little as 8 hours on the ground in London. What you can get done during that time depends a lot on what you want to do and what time of year. You could spend the day on a Ho/HO bus. Or just visiting a museum or two. Or spend the entire day shopping. There are tons of great things to do in London, so you have to decide what's important to you before anyone can suggest an itinerary.

I have Rick's London guide 2013 edition and it doesn't have itineraries/plans on taking a one-day tour in Paris, so I must have a different book. He does cover using the Eurostar to travel to Paris under his "London Connections" section, but little else.
We're traveling the last week of September. We enjoy walking. We want to view the main sites (particularly those in central Paris or easy to get to) such as the Triumphal arch, Eiffel tower, Pont Neuf, Concorde Square, The Holy Chapel, Notre Dame, etc. We want time to do some strolling down some romantic/scenic boulevards, have a nice lunch somewhere, actually tour inside Notre Dame, and take a 1- hour +/- river cruise, and take a quick look inside the Louvre to see the Mona Lisa. We don't plan to go up into Eiffel tower. And if there is time, add some other sites. We don't really know much about getting around, and/or putting a plan in place to do this and don't have a lot of time to much research. I have seen some guided tours for roughly $335 that take the 7:00 rail in, but that's pricey. Any help is appreciated. - Joe

Too bad looks like he got rid of that chapter. Here's the condensed version: http://www.ricksteves.com/plan/destinations/france/0399paris.htm

Hi Joseph,
We considering doing it the opposite way, Paris-London, when we took our daughter to Paris for New Years. We had been to London and she hadn't. Eurostar tickets were expensive because we weren't purchasing them far ahead. Then there was the cost of actually being in London. We decided not to do it. I would suggest two different ways to do this. The first one would be to take the Hop on/Hop off bus. It will give you a good overview of Paris and you can get on and off at the sites you want. The second option that comes to mind is to concentrate your sightseeing into a geographical area that you can mostly walk from place to place. Most of the places you specifically mention fit into that category, with the exception of the Eiffel Tower and Arc de Triomphe. You could metro to those locations. I don't know know that you would have time to do a river cruise. To experience the river you could take the batobus (a boat bus) that has multiple stops along the river. You could get to the ET that way instead of the metro. You have to check in for the Eurostar at least 30 minutes early, so don't forget to allow time for that. Good luck with your planning.

Joseph, Before you put too much effort into putting together your day in Paris, have you put your date and times into the Eurostar.com website and been sure that the price is one that you can accept? I ask because this close to travel you are likely to be looking at basically walk-up price tickets - the cheap ones were put on sale months ago and are probably gone by now. I've never made the trip as a day trip, although I have been through the Channel Tunnel many times including many Eurostar trips. When I go to Paris it is always for several days. But if one day is all you've got, its all you've got - unless you can spend time in Paris on your next European Holiday. Can I suggest that you lower your expectations on seeing the Mona Lisa - lower them quite a lot. The actual paining is very small, behind protective shields, and the room is always full of wall-to-wall tourists all pushing and shoving to get reasonably close. It is especially hard to see because, despite the signs forbidding photography, people are constantly taking pictures, most using flash, and the flash bounces off the plexiglass meaning that most of the time you are looking at a white flash rather than a painting. Not to speak of the selfies with them and sort of the painting. That particular room was the low-light of that visit to the Louvre. Thank goodness I also had about three hours to see a few other rooms, including the furniture which I thought well worth seeing. The advice about the minimum 30 minute Eurostar check-in deadline is no joke. There is airline type security after check-in, and Eurostar won't let you go if you are late to check in 30 before. That's through the check-in gate, not in the line waiting to check-in. So that's at St Pancras before 5am in London.

Joseph, I checked the Eurostar website for last week of Sept and cheapest round-trip tickets I saw were $302 in standard class (those are non-flexible/non-refundable fares). At that price maybe the guided tour you mentioned would be the way to go.

The 05:40 train is in general the cheapest of the day available at any one time as it fills up slowest because it is so early. However, the £29.50 tickets are long gone - the cheapest one is about double that.