I traveled to London December 20-29th with my two teenage daughters, 17 & 19 years old (one of whom is neurodivergent). With some airline credit that was set to expire at the end of 2023, we decided on a trip to London over Christmas (I've been before, first time for my kids). At first, I was hoping to split our time between London and somewhere like Bath or York, but between general transit restrictions Dec 24-26 plus scheduled repair work on certain lines, we decided just to stay in London for the full 8 nights. Overall, we were focused on history, art, Christmas festivities, markets, and street food.
Day 1 & 2 / Wednesday-Thursday: Seattle -> Heathrow on Virgin Atlantic. Happy we were able to get out of Seattle as heavy fog was rolling in (and resulted in various flights getting delayed or diverted not long after we left), we were hoping to get 4-5 hours of sleep on the flight over and probably all got somewhere between 3-4, though landed shortly before 10am feeling ok. We were at Paddington station by 11am via Heathrow Express, I had pre-purchased tickets about 3 months prior to get discounted rate. I opted for a taxi to our AirBnB in Pimlico (~25-30 minutes with traffic, £20) so my kids could see some of the city enroute. We were able to check in early and were out the door by 12:30p to start exploring. Our plan was to take the tube to Covent Garden and slowly walk back, exploring lights/shopping/people around Covent Garden, Trafalgar Square, St. James' Park, Westminster Cathedral (not Abbey) on our way back to our apartment. I ended up opting for Oyster cards for them since neither of them had contactless credit cards. It's not the cheapest way, but it was the easiest for them and worked great for us (I used my contactless credit card for all bus/tube rides the whole trip). Deeply regretting taking the stairs up at Covent Garden station - a 3 story spiral staircase that nearly did me in after jetlag/fatigue/not eating - we were thrust into the heart of a very, very busy Covent Garden. Lots of walking around and exploring, stopped into the Neal's Yard food hall for snacks, plenty of street performers and holiday lights. On to Trafalgar Square and a quick browse through their Christmas market. Most stalls were not so much artisan things as they were more mass-produced goods in the realm of hats, mittens, ornaments, pottery, etc., but a lively crowd and plenty of food to choose from. We walked through St. James' Park as it was getting dark, quite empty but felt safe, and took in the sights along the way. We picked up a few things at the Cardinal Walk Marks & Spencer, then popped into Westminster Cathedral for a few minutes before finally arriving at our apartment around 6pm.