Last spring, my wife and me took the chance to spend a child free long weekend in Utrecht, the Netherlands. We had a blast, doing some sightseeing (like visiting the Rietveld Schröder House) or relaxing in the oldest outdoor pool of the Netherlands.
The place near Sinte Marie was special. There were university people with their books and other people with their joints, none of them bothered about the others, all enjoying the sun and having a good time.
The area around Oudegracht is beautiful. Touristy, but beautiful. There are lots of cafes and bars located directly to the river, where you can have a good meal and a drink and watch the boats passing by.