2 days in London

In order to see the White Cliffs of Dover, you need to take a ferry across the Channel, not a Eurostar train through the Channel Tunnel.
Eurostar Brussels to London takes 2 hours city centre to city centre, a ferry takes about 1½ hours to cross the Channel, but Brussels to London this way will take most of the day.

The ferries are the cut-price end of the market, it is a lot faster through the tunnel. they don't cater well for foot passengers, no money in it. They are designed for cars and road freight that is not time sensitive, squeeze them in.
You would need to:

• Multiple trains Brussels to Calais
• Local bus or taxi to ferry port
• Ferry Calais to Dover. Two companies on this route: http://www.poferries.com/eu/calais-dover and: https://www.dfdsseaways.co.uk/ferry-routes/ferry-to-france/dover-calais
• Stand on deck for the trip to get the views of France receding and England getting nearer.
• Local bus or taxi from Ferry port to Dover station
• Train to London.

Alternative is to take a day out of your London trip, take a train to Dover and visit the castle, and walk along the top of the cliffs.
With only two days I don't think either option is possible.

Are the Cliffs the side trip or is London? I think Chris describes the challenges of seeing the Cliffs. In the Southern England tour, RS gives one whole day to Dover and that is after sleeping in Canterbury. Give a little Google and see what folks have said on a few other forums. Only you can decide if it is worth one of your two days.

Two days in London? I am a huge fan of the Globe. Check out their website and view What's On and order tickets if a play appeals. I also like walking, so I could see building my two days around the South Bank (Globe, Borough Market, etc) and the opposite side of the Thames. So many sites to see.

And, consider London Walks - many varied itineraries.

Is a two-day London stop worth it? To me, yes. Most of my London trips are a few days only as I usually fly via Heathrow to and from Philly. You can also Google 2 days in London and read how other folks have spent their time.

Hope this

I'd always go for 2 days in London!

For 2 days here are some ideas to fill a day:

-Tower of London, then take the boat to Westminster and head to Westminster Abbey
-British Museum (filled with amazing things like the Rosetta Stone, the Elgin Marbles from Greece, mummies and the Lewis Chess Men and it's free), then walk to Covent Garden then Trafalgar Square
-Museum of London and St Paul's Cathedral or a London Walk
-Churchill War Rooms, Horse Guards and Westminster Abbey
-Tower of London -> walk to Leadenhall Market (Harry Potter reference) -> St Paul's Cathedral
-Victoria and Albert Museum -> Science Museum
-Trafalgar Square to Horse Guards, walk thru St James' Park to Buckingham Palace, then thru Green Park to the RAF Bomber Command Memorial, then continue thru to Hyde Park
-Windsor Castle
-Any one big site + London Walk

None of the museums listed are really Art Museums if that is what you might not be keen on. You can add National Gallery if you do enjoy art.

Save Dover and the white cliffs area for a trip when you have a week in London.

I’m confused are travelnewbie16 and the OP halfdozmom one and the same?

Thanks for all your help!! I think we have it figured out :)