I like visiting the markets...Old Spitalfields, Greenwich, Maltby Street. I usually check out what is being exhibited at the Victoria and Albert museum, too. If you have time, you might want to see if you can score a last minute ticket to a show in the West End.

I'm a museum geek and could have easily spent weeks soaking them all up in London. The British Museum is like heaven on earth to me, and I was surprised at how much I loved the V&A and the National Gallery. Definitely take in a show if at all possible. London theater is an experience not to be missed!

The last time I stayed in London proper I spent close to 6 hours getting a tattoo at a well known studio. You might not be up for that kind of excitement though. ;-)

Wonderful that you're doing another Camino. I would imagine that can really get into your blood.

Although you said you didn't want to run from Museum to Castle, you really should hit the British Museum and the British Library. The Tate, the National Gallery, the list goes on depending on your interests. (A favorite off the tourist-tier choice is the Wallace Collection, in a fine townhouse).

I believe you can still get discount tickets at the TIKTS booth in Leceister Square. Fab shows at a very high quality, far less than NYC or even your local touring production.

Neighborhood-wise, there is a bit of flavor for everyone, if you want to get an idea of everyday life. What might appeal? High end? Bohemian and transitional?

Knotting Hill has some fun bookstores and antique shops to browse.

Definitely the National Gallery is my choice. Free and I like to go browsing for a couple of hours every time I am there. It’s on Trafalgar Square so IMO it’s a bonus because you get the terrific experience of that, plus the view down toward the Thames and it’s a fairly short walk to Westminster. Take a side trip over by Whitehall and duck into Churchill’s War Rooms for a couple of hours of a self-guided tour thru the underground where he ran the war. They have also added a museum of his personal effects.

I also enjoyed many of the London Walks tours. Get the guide and pick one in an afternoon or evening. They are a couple of hours long and you meet at a Tube stop and pay the guide. Fun and interesting.

You can spent a couple of hours seeing the high points or many hours in he British Museum. I also enjoy the Tower of London if you want to see the Crown Jewels and a lot of history. Allow at least half a day.

We were in London last summer and revisited our favorite sites. DH climbed to the very top of Saint Paul's Cathedral, while that is a big effort, you can climb to the whispering gallery and stop there. Visit Tower Bridge and Notting Hill. We stayed in an AirBnB in Notting Hill and really liked the area. Wander around Kensington, a feast for the eyes is the Churchill Arms Pub, a good spot for a bite to eat:

I LOVED just hanging out in Piccadilly Circus and Soho at night! but I'm a people watcher. :)

ETA: Visit Kew Gardens and be sure and stop for pasties.... also loved St. James Park!

Depends on your interests, obviously. The museums, most definitely. In addition to the ones mentioned above, I’d also suggest the natural history museum.

If you’re into literature, you’d find residences of poets, playwrights and such marked on the outside the buildings, especially in the Kensington and Chelsea area. There is a guided walking tour too. I explore it on my own whenever I’m in London because we stay in that area and get chills every time I see one.

If you’re into soccer, you may like to visit the Chelsea stadium. I took my son the last time we were there because he’s a soccer aficionado. He loved it.

And of course, the parks. I can spend hours in Hyde Park.

Tower of London and make sure you do the Beefeater Tour at the Tower of London. It is so good. You can get tickets online.

https://tickets.london/gt/tour/tower-of-london-tickets-with-beefeater-tour/58?ref=nav

I second London Walks. They will be listed on line and happen during the day and into the evening. They usually have a theme to them and we did the Jack the Ripper talk.

http://www.walks.com/

Those London Walks sound great! A lot of variety and good prices.

Been there 3 times. London is full of whatever you want! I advise pursuing what most interests you at home. I avoided the Must Do places... can see those online! I enjoyed most being an outdoor lurker/gawker - strolling, riding buses and trains, sitting in parks. Eating when and where hunger led me. A singer, I stumbled into St Martin's in the Field noontime concerts and an Evensong at St Paul's Cathedral. A play lover, fine memories of all plays seen in pub theaters, the Globe, and in West End (but 2 operas not so much). Museums can have too little light for me, or too much walking and standing. If you have favorite British authors, track down their haunts (easy to find online). "Time Out" on newsstands will (or used to?) list what's happening that week and will include off-the-beaten-track events (that you may never find, but can lead to some other adventure). Eat where people share tables - pubs and tour site cafes - it's nice to make new temporary friends!

There is so much to see at the British Museum that I always plan to spend a full day there each time I visit. If you want a panoramic view of London, and don't want to pay for the London Eye or the Shard observation tower, get tickets for the Sky Garden https://skygarden.london/sky-garden

Here's a couple other ideas.

Take this tour from Eating London:

https://eatinglondontours.co.uk/twilight-soho-food-tour/?_ga=2.152532857.1152565095.1526955613-1802704768.1526955613

And eat at Dishoom for fantastic Indian food:

http://www.dishoom.com

Thanks for the food tour suggestion. Since I'll be solo, it's nice to do a food tour to have others to dine with.

How about a Hop on Hop Bus? Just to get the "lay of the land" when I first arrive. My flight lands about 11:30 am, so I'll probably be able to get to my room by about 1:00, so I'll have a whole afternoon the first day.

Oooh, Skygarden looks great - and free entry!

I forget which walking tour it is, but one goes through Westminster Abbey and bypasses all the long lines if that is of interest to you. There are other outside portions of the walk too, but it is a great way to see a large portion of the Abbey with a guide.

My friends and I did a pub walk one evening that was fun, and the secrets and spies walk was great. It’s been a couple of years, so there are probably different ones now.

edited to add, the hop-on, hop-off bus tour is a great way to browse the city the first afternoon and see a lot of things you want to just ‘see’ and photograph quickly like the Palace and a few other things. Then you can return the next day either by tube or bus for the longer tours or walks.

Go somewhere for a fancy traditional afternoon cream tea. Lots of the high-end hotels and restaurants offer it. I go to GB somewhat often, and doing that was one of the funnest things I did in London. I'm more of a "hike in a garden or park" kind of gal and when there mostly visited friends, so can't recommend much in London. I'll bet, just like in NYC, there are bus tours and they were fun in NYC so I'll bet they are fun in London too.

I forgot about Old Spitalfields Market. Lots of lovely food and all sorts of stalls to browse . We met some people there for lunch one day, and with all the places to choose from, we independently picked the same chicken stall. Look for the place with the long line. It's worth it.

The first time I went to London, I was by myself for a day before meeting up with DH after a work conference. I did the hop on/hop off bus tour and it was a great way to get an intro to the city.

If it’s nice out, I’d wall through the parks and also try to get to Portobello Rd market. I visited my son last spring when he was studying in London, and we walked at least 10 miles a day, just exploring.

Westminster Abbey! I was treated to a choir rehearsal when I visited. Plus, unlike some museums that send their treasures on tour, the beauty of and history in the Abbey does not tour. Hop on/off then walk, walk, walk. Just pretend you're still on the Camino.

I suggest getting an Oyster card so you can use the bus and subway easily. You can buy them at automated kiosk before entering the subway at Heathrow.

I'll second the Portobello Rd Market. I'm glad I had room in my suitcase for the treasures I bought there and keep in mind that they are open to negotiating on the prices.

All museums are free (a donation are welcomed, but not required), at least all the ones we visited. My favorite was actually the natural history museum. British museum is nice too, but was much more crowded and I'm not huge on crowds so may be why it was knocked down a notch.

For people watching and a nice day Hyde Park is nice. It will be full of people, but still not feel crowded and lots to see other than people. The Kensington Palace is there too. We didn't do the tour as we didn't feel the price was worth it at the time and with the other things on our plate it didn't rate as high. However, I grew up in Europe and have seen/been in plenty of castles/manors/palaces so not really my thing. Natural History museum is basically around the corner from Hyde Park.

Hop-on-hop off can be nice especially if you want to see some of the well known buildings/monuments and are tired of walking. You can choose to get off if you want a closer look or just view it from the bus.

Tower of London - I found it very interesting and appreciated all the tour guides in their particular areas. I'm a history buff though. Unless you really love seeing jewelry the wait and line to see the crown jewels may or may not be worth it to you. I really wasn't that interested in it, but my friend was so I tagged along to be a good friend.

Tower bridge - the glass floor and laying down on it and looking down was cool for this gal who is afraid of heights, and I liked the tours/videos that walked through the history, but I wouldn't spend the money again as I thought the value wasn't there.

Near the British Museum is a large shopping street (Oxford St) - Typical chain stores, but also Selfridge, so if you've seen the British TV show - Mr Selfridge it might be cool to visit. Harrod's is in another shopping area and depending on your interests might also be worth a visit.

I agree on seeing a show while there if you like musicals. I have every time I've visited. You can purchase ahead now or there are places at Picadilly Circus where you can purchase from all, but will be more expensive. Some sell out though and those will often have a lottery on their door step for extra tickets they have available after a certain time. Since you only need single seating this might be the way to go. We did this one time and didn't get the tickets. The ticket booths that sell to all shows was useful to us in knowing what shows still had tickets. We then took our chances and went straight to the theater to purchase the tickets as it was a lot cheaper. There is also a normal chain store shopping area here. Has a bit of the same feel like NY Times Square, but with a London twist. It is not that far from Hyde Park and Buckingham Palace and St James park (across from Buckingham palace).

Oh Beer, wine, and ice cream are available at all shows as well and you get to bring it in with you to sip/drink/eat during the show too.

All the above suggestions are great and I have one addition. It is well worth you time to visit the Liberty Department Store. The structure itself is wonderful. It is a very old timber framed building with structure exposed inside and out. Also I love textiles and their fabrics are some of my favorites. I spent hours just browsing the fabric section. It's near Chinatown and the theaters, so you can get a bite and see a show. Have a great time.

Following up - I had a great 2.5 days in London. I added on a night because I got a great deal on my accommodation by staying in a University dorm room with private bath instead of a hotel. The dorm that I chose was Goldsmid House. Definitely not 4 star accommodations, but since I was mostly only in the room while I was sleeping, the 57 pounds a night I paid was well worth it. It was very close to Victoria Station, and easy to get around the city from there. I can't even tell you everywhere that I went. According to my fitbit I walked 20 miles a day while I was there. I got a ticket for the HOHO bus when I arrived, to get an overview, and my ticket included 3 free walking tours and a short Thames cruise. I did refer to this thread while I was there, and enjoyed a lunch at Old Spitafields Market, and went to The National Gallery and the Tate Modern. I spent about an hour or so in Harrod's - what an amazing place! I mostly just enjoyed being in the city, and had absolutely perfect weather!