Utrecht

Canal boat ride around the city.

Visit the extraordinary Rietveld Schröderhuis (needs pre-booking)
https://www.rietveldschroderhuis.nl/en/

Go up the Dom Tower: https://www.domtoren.nl/en/

Visit the Miffy Museum - Miffy is known as Nijntje in her hometown of Utrecht: https://nijntjemuseum.nl/en/

Look in real estate windows and dream about moving to live in this perfect small city.

Wander the beautiful streets and canals - there are waterside restaurants on the lower level next to the water. I can’t recommend any particular ones as I can’t remember where I ate, but the ambiance is lovely.

Also: the big modern train station is near the middle of town and it’s easy just to tap and go on a train to a nearby town - I had a lovely half-day trip to Gouda.

I was in Utrecht for 5 nights last May. We stayed in a cozy neighborhood that was a 20 minute walk to the train station. Although I enjoyed exploring the major sights in the Old Town, my favorite times were just walking around and exploring away from the tourist spots. Some fun discoveries were Griftpark (full of locals and farm animals) and Tijm (yummy restaurant we ate at twice).

Golden Girl mentioned some great ideas for things to do in Utrecht. You also have many day trip options at your fingertips. By train, we visited Woerden, Gouda, and Den Bosch. My favorite was Woerden. We went on a Saturday, so there was lots to do. Their cheese market was small, but not overly crowded and very hands-on. We visited the local windmill and bought cake mix from the miller! Gouda is also a nice spot to visit. For some sweet fun, check out the Kamphuisen Syrup Waffle Factory tour.

In general I don't find the food in the Netherlands or Belgium to be to my taste, but O'Panuozzo in Utrecht makes terrific pizza in the Neapolitan style. LOOF also made us good dinners.

Broadway American Steakhouse, a little hard to find, as it is down some stairs on to the canal.
Have eaten there 4 times now, excellent, from the shrimp starter, to main, and the Cheesecake .

Utrecht has some superb museums. Because the Museum Speelkok Utrecht is only by guided tour (musical automaton instruments), you might want to book the English tour in advance, since it often sells out.