Bruges itself if a beautiful little city. We spent hours just sitting in the main square just drinking coffee or having lunch. The canal tour is a must and there are plenty of places to pick up a boat and do this.
The old historic building are well preserved and very pretty and of course there are chocolateries and lace shops galore.
Some people were also taking a carriage ride, which we did not have time to do, but looked good.
Ideal place to see in a day.
Rotterdam itself is a modern city, and we only drove through it on the way to Amsterdam.
Hard to judge a city in the pouring rain, and the royal palace, one of the main attractions, was covered in plastic. A canal tour is a good way of seeing plenty of the city without too much walking and without getting wet.