My young adult children and I will be enjoying the Christmas season in Europe this year. If you've been, or are a national of the country, I'm interested in learning favourite Christmas tradition in each of these areas:

London
Paris
Normandy Coast area
Amsterdam
Interlaken

In Paris, we enjoyed chestnuts, roasted and hot, from street vendors.

I've spent Christmas or earlier in December in London several times. My favs are the Pantos (one really needs to attend one to even start to understand ), roasted Chestnuts and other street fare, the Christmas lights on many shopping streets, the windows at Fortnum & Mason and (sometimes) Harrods, Borough Market (it runs year round but is special over the holidays), carol and classical concerts - especially Handel's Messiah which is usually presented multiple times at multiple venues, Christmas ay Kew, Lighting of the Christmas Tree and singing carols afterwards in Trafalgar Square, and the ice skating rinks -- there are several but I like the one at Somerset House the best, Christmas markets on the Southbank and lots of other places all over town . . . and more.

London- Christmas Eve at Westminster Abbey. Tickets available in Oct/ Nov.

Panto, it's behind you
oh no it isn't
until you've been to one you will never understand

I consider the Musée des Arts Forains in Paris a must, starting December 26th. (It is only open for private events in December before that date.)

We went to a few pantos while living in the UK and one (in English) in Basel after moving here. Not a fan. They're like opera -- either you love it or you don't. So take in one if you think you and the family might like it, but I wouldn't buy tickets for more than one without seeing one first.

From Interlaken, you might enjoy the Christmas market in Thun, a short train ride away: https://www.myswitzerland.com/en-ca/...htsmarkt-2022/ And of course, the winter activities in Wengen, Grindelwald, Murren etc (cross fingers for a good early snowfall). A shame Ballenberg doesn't open up for Christmas. There is also a market in Spiez, which is even closer than Thun: https://www.spiez.com/en/events/high...chlouse-maerit Since you will be spending time in three large cities, you might want to go smaller in Switzerland, but nonetheless, the city of Bern is lovely in the winter. You can try some of the traditional dishes like raclette -- but beyond cheese, chinese fondues are very popular here. Reservations advised, esp if you will be in Interlaken over Christmas itself. Note: unlike London, Switzerland's public transport systems (trains, buses, etc) will be up and running on Christmas day, but on a slightly reduced schedule (similar to the regular Sunday schedule).

How long will you be spending in each destination? Are you doing most of your travel by train?

How long are you in Europe? When exactly? Are you planning on visiting all those places? How long will you spend in each/any of them?

Not really Christmassy but worth a visit, assuming it goes ahead in these expensive times, is the Amsterdam Light festival.
https://amsterdamlightfestival.com/en

there is usually an ice rink on the Museumplein and lights and trees and stuff as well, but again with the high price of energy Things may be less than previous years.

Some museums are open on Christmas Day but you still need to buy tickets online for timed entry.

Remember Covid is still around and worse in winter, so make sure you can cancel anything just in case.

Check to see if there any processionals that lead up to Midnight Mass. That was very memorable for me.

Christmas is not the main festival in December in the Netherlands, Sinterklaas (St Nicholas) is. He 'arrives' in the Netherlands this year on 12 November. That is a really big public event, but the actual day of his birthday, when Dutch children get presents, is on 5 December, so there is a month of anticipation and nightly TV reports on his preparations with his offsiders, the 'pieten'. The night of the 5th is celebrated in the family. I don't know if you will be in the Netherlands that early but the arrival would be a uniquely Dutch thing for you to see. The arrival rotates between different towns but this year it will be in Hellevoetsluis.

Dutch kids still get presents at Christmas but it's not the same kind of festival as with 'de Sint', which is much bigger and more festive.

Lavandula

Some additional Christmas activities liked by families: Sadler Wells Christmas productions (the girl with matchsticks by Andersen is atmospheric with outstanding music). Hyde Park Christmas market. A Christmas concert at The Royal Albert Hall or the Royal Festival Hall or Barbican.