London with a 12-year old

Imperial War Museum, and the Transport Museum are worth considering. The Science and Naural History Museums have lots hands-on displays as well. Touristy and a bit expensive but most 12-year olds would love the the Madame Tussauds and/or the London Dungeon (be sure to purchase tickets in advance).

The Science Museum and the Natural History Museum, both free and next to each other, might be more fun than the CWR. The View from the Shard, whilst expensive, I'm assured is worth it, especially around sunset.

And again expensive, super expensive!, about £100 per person, but a lifetime experience, is a helicopter ride over London from Battersea Heliport.

A tour of Wimbledon isn't cheap but not much in London is. There's an interactive museum and your son can get his picture taken at the player's podium. There were a few kids on our tour and they seemed to be having fun.

The British Museum can be overwhelming, however my SO (who is pretty much 12 on the inside) didn't want to leave the mummy exhibit. Until he saw the Viking exhibit. And the arms and armor exhibit. You see the picture.

Jack-the-Ripper tours go through Whitechapel at night. The derelict buildings, of course, are long gone but placards and stories remain. The neighborhood is Bangladeshi now and quite safe-we rented an apartment there on our last stay and walked the streets after pub closing with nary an unknown slasher around ;)

Does he like boats? Hubby and I (sans children) went on the Golden Hinde (near the Tower Bridge) and it was quite hands on (well, for the 5-6 kids in the group - they seemed to thoroughly enjoy it)...and boys seem to like gross stuff, so hearing about the living conditions on board the ship could be just gross enough for pre-teen boys!
http://www.goldenhinde.com/

I know I'm repeating myself, but http://www.jasons.co.uk/

Is your 12 year old studying ancient or medieval history in school this year? Our 12 year old granddaughter is in 7th grade and has been talking to us about what things she can see this summer in London at the British Museum. Take a look at your son's textbook and see what the 2 of you can find to look for around the city and especially at the British Museum.

When I took my daughters (9 and 11) to London, we spent a great day by riding a double decker bus to Greenwich for the Prime Meridian and the maritime museum and then we took a boat to the Tower. By then, afternoon, the bus loads were gone and we enjoyed the Crown Jewels and the buildings without crowds.

Consider the Hop-On-Hop-Off bus tour. Very exciting for a 12-year-old to see all the sights from the top deck of a sightseeing bus. HOHO bus goes by every major tourist sight in London.

Your ticket is good for 24 hours. The first thing you want to do is to board the bus, and do a complete loop around their London route; takes two hours. That way, you will get a look at all the tourist sights. A ride over Tower Bridge gives you a great view of the river. If you are on the top deck of the bus, you have a great view into a lot of gardens and private fenced areas of townhouses in posh areas. It is also relaxing, because you are seeing a lot, and not having to deal with walking or the tube.

A long ride on the HOHO bus is a great place to bring along a sandwich, chips and drink. Eat your lunch while enjoying the sights.

Piccadilly Circus and Trafalgar Square are sights many tourists want to see, but there's not much to see there, except for the lion statues. I would suggest a drive-by, on the HOHO bus. You go by Buckingham Palace, so you get the excitement of getting a good look at it without having to walk there and just stand around.

You can also get off the HOHO bus anytime you wish, see a sight, then hop back on the next HOHO bus that comes by. Very convenient.

Your HOHO ticket also includes a boat ride on the river; a pleasant break from being inside museums all day. Interesting to see the great sights from the water. And a boat ride on the River Thames is bound to be exciting for a twelve-year-old.

At that age, our kids loved Windsor- both castle and the town. You can take a short 'cruise' on the Thames from near the Eaton bridge. It's about a 25 min. train trip from Paddington station in London with an easy change at Slough. Trains run every 20 or 30 min. so you can come back easily if you wish and only stay 1/2 or 3/4 of a day. We often did this on days when we had theatre tickets for the evening.

My boys loved the Whispering Gallery in the dome of St. Paul's cathedral, it was a great experience for them to "talk" to each other from opposite sides of the dome.

Went this past Sept. with my family which included 2 12 year old girls. They loved all the museums but they really enjoyed the Harry Potter Studio tour. If your son is a fan, you might want to look into that. Don't know if tickets are still available for the dates you are going to be there but you do have to buy them in advance. Train trip for London is only about 30 minutes or so, and very easy to get to.

London Eye is a tourist favourite, a huge Ferris wheel on the river bank. Not for me: I'm getting dizzy just thinking about it, and the admission price takes my breath away too. Its website also promotes short river cruises so that could be convenient. https://www.londoneye.com/

Just returned from 9 days in London/Paris. My kids really enjoyed a walk thru Hyde Park and seeing the ducks and swans. Twas on our first day and the time outside helps reset the body clock to reduce jetlag.
London Eye just goes slowly to load each carriage and never spins around like US ferris wheels. We skipped it.
It was too chilly for us, but for July the high-speed boat tours on the Thames look like great fun.
Be sure to climb stairs wherever you find them. Especially the rotunda of St. Pauls.
I hear glowing reports from the day-long Harry Potter studio tour, I believe in Leavesden (sp?).
RAF museum if he is into aircraft.

Kids need to get out and be active - take him to St. Paul's to climb the tower, or to the Great Fire memorial (almost next door), which also has lots of steps! London Walks has some great kid-friendly walks (two hours, start and end at a Tube stop). Would he enjoy the theatre? There's bound to be something on offer that would appeal to him. The "Duck" tours are fun - part on land and part in the river (reserve early!). Take a ride on the "Boris bikes" - conveniently located all around Central London. The Eye is expensive - and the lines can be long - but on a clear day it is a great view! (Not sure I'd bother with HMS Belfast unless he's a "boat buff!")

p.s. Get Guy Fox's "London Children's Map" - its fun to use the stickers as you visit the places. (Or maybe he's too old - I used it with an 8 year old and she loved it!?)