What City Shall I Visit for Winter ?

Switzerland is far away from the Amsterdam - Paris itinerary.
Low cost flights Amsterdam - Switzerland.
Train connections from Bruxelles to Switzerland via Paris.
Departures from Bruxelles at 8.15, 9.13, 10.37, 11.15, 12.37, 13.15, 14.37, 15.15, 16.15, 16.37, 17.15; 5 1/2 to 6 hrs ride up to the Swiss border
May be you will have a look at
http://www.myswitzerland.com/en/home.html
http://www.swisstravelsystem.ch/en/

What do you want to visit in Rotterdam? The Maritime Museum? And do you want to make a little cruise in the port?

There is almost no old architecture in Rotterdam, only new.

@neckervd :

Yeah, i know that it takes long time from Brussels to Switzerland. But we want to spend our last day in Paris instead of in Switzerland.

What city should we visit then ?

@wateenmooiedag :

We dont wanna see old architecture in Rotterdam.
We'll go to Kinderdijk/Delfsheaven/etc (we dont know much about Rotterdam)

Edited by: handisetyadi

I don't quite understand why you've picked Rotterdam and Brussels; Kinderdijk is outside R'dam and only worth it if the weather allows, Brussels is nice but there are several nicer towns in Belgium.

People go to Rotterdam for it's modern architecture or it's port, but it doesn't make much sense to go there and see Delfshaven; if you want to see historic architecture, it's better to stop over in Leiden, Haarlem or Delft.

Why do you want to travel from Paris to Geneva and back for only 2 days if you don't even know what you will do at Geneva?

A lot of old buildings where destroyed in Rotterdam during WWII . Leiden, Haarlem, Utrecht and Delft are much better choices.

Maybe it is better to visit the open air museum Zaanse Schans instead of Kinderdijk: http://wikitravel.org/en/Zaanse_Schans#b . There are more different things to see in the open air museum than at Kinderdijk.

Ghent and Bruges are excellent choices in Belgium.