This was a trip in August 2014 for three nights – one in Cologne and two in Amsterdam.
Click on the links for information about each leg of the trip :
London to Cologne – Eurostar to Brussels then German InterCity Express to Cologne
Cologne – one night at a mid-range hotel near the Cathedral
Cologne to Amsterdam – by German ICE
Amsterdam – two nights at a budget hotel near Dam Square
Amsterdam to London – via Thalys to Brussels, then Eurostar