Where to travel from London?
Maxi
Get out of London and see the real UK
sunshine_mel
Given that you'll only have 5 full days (once you've factored in travel), I'd honestly suggest you just pick one location and see it properly. You could fit in both Paris and Amsterdam - but you'd get very little time in either.
David S
Why don't you take the opportunity to explore the U.K. which is a beautiful, historic and very varied country away from London. if you are going to Europe take the Eurostar and other trains rather than flying so at least you see the countries you are passing through.
nico
Get out of London and see the real UK
Gypsyfish
I doubt that you'll find much of interest in Belgium or Luxembourg. Depending on what you mean by absorbing the culture, you could just go to Paris. It's worth a stay of several weeks. Or you could travel around the UK. It's only a few hours by train to Edinburgh, and a short flight to Ireland. What kinds of things interest you when you travel? You can't beat Paris for art, food and people watching. You can't beat England for charming little towns and history. You can't beat Ireland for scenery.
trailblazer
For 5 days I'd just explore a bit more of the U.K., travel to Edinburgh spend a day of two there and travel down to York or Liverpool, again a day or two, then make your way back to London, Windsor is worth a day stop off and is just a 30 min taxi ride from Heathrow. Travelling to othe European countries sounds good, but with all the journey time, you won't get long enough or end up in just one location, Ie Paris or amsterdam
Siddhartha
Paris and Brussels will be best - Lux is crap and nothing there worth seeing.
Bookbinder
Yorkshire is the place to visit, without a doubt! If you desire history, the city of York will suit you. Every age has left its mark on York, from the Roman age to the present. If you are more of a landscape and scenery lover, look no further than the Yorkshire Dales, the North Yorkshire Moors, or the Yorkshire Wolds. Whilst you admire the views of Yorkshire's lovely countryside, you can easily be distracted by the pretty villages and handsome towns that are there. For dramatic views, nothing can beat the view of the North Sea from Flamborough Head, or from Scarborough Castle. Your 5 or 6 days will surely be very well spent in Yorkshire, and I do not doubt that you will return home thinking that you would love to see more of the interesting and beautiful county of Yorkshire. Please come and visit us! You won't be disappointed!