Day Trip from London to Stonehenge (ahem - and maybe Windsor Castle?)

Trying to do two destinations that both interest you on an organised tour is a recipe for disappointment. The simplest way to get to Stonehenge is to take a train from Waterloo station to Salisbury and then the regular bus shuttle to Stonehenge from outside the station. Try and leave some time to see Salisbury and particularly the cathedral.

Exactly when will you be in London? British Summer Time ends on 26th October and the clocks go back an hour, so darkness will arrive an hour earlier in the evening.

Hi! I agree with Johnew52. If you take a tour that includes both destinations, they will both inevitably be shortchanged.

For Windsor, please do not neglect to walk over the bridge and into Eton. It is delightful. If you search for advice on Windsor and Eton in this forum, you will find lots of particulars.

Enjoy!

I doubt very much it will be crowded in October, and you will be there before the school half term when more people can be expected.
However if you want to be there just after opening time, and 45 minutes before the first tour bus from Salisbury the way to do it is a route not in the guidebooks.
Take the 6am train from Paddington to Swindon, then the 0725 bus 49 to Devizes changing into the X2 to Stonehenge.
Two hours later you can take the next X2 service into Salisbury.
That gets you into Salisbury Tesco at 1220.

There is a train back to Waterloo every 30 minutes taking 90 minutes.

So if you don't go to the Cathedral or anywhere else in the city you could be back in London by around 2.30 pm.

Total bus fare £9 each.

You have good advice about Stonehenge on you other thread. See the very last post here, by Pam:
https://community.ricksteves.com/travel-forum/england/exploring-options-for-a-8-10-day-vacation-to-london-w-day-trips-to-stonehenge-and-liverpool

You wrote:

I've seen videos of travelers that booked tours that combined visits to both Stonehenge and Windsor.

If that's what you want, search for several companies that all do a variation of this.
Evan Evans tours
Premium Tours
Golden Tours
International Friends tours

Many of the "regulars" here on this forum would do the two trips separately, on their own, spending more time than you'd get on a quick tour.

Better than the big bus companies that do day trips, browse London Walks, here: https://www.walks.com/day-trips-from-london/

You spoke of doing 10 days in London. Consider spending a couple of nights somewhere else. To get a real taste of England, you may want to spend the night somewhere besides London, say, in Salisbury, Bath, Oxford, or the Cotswolds. If you are leaving out of Heathrow airport, consider spending one or two nights in Windsor at the end of your trip. It's a short distance from Windsor to Heathrow. Take a taxi; it's not expensive to be delivered right to the door of your departure terminal.

Thanks for the helpful advice, everyone.

Rebecca - Thank you so much for reminding me about Pam's post on my other thread. I meant to add that to my notes re: Stonehenge.

Much obliged!

You're welcome. Do browse the London Walks, here:
https://www.walks.com/day-trips-from-london/

They do themed walks around London, too:
https://www.walks.com/