When people think about the Netherlands, they usually think about Amsterdam. Amsterdam is a very attractive place due to its canals, its culture of tolerance and its museums. However, the Netherlands is more than Amsterdam. If you want to experience the "Amsterdam vibe" in a less frenzy environment I strongly recommend to spend a couple of days in Utrecht.
The main attraction in Utrecht is the Oudegracht or old canal. One of the most remarkable aspects of the Outdegracht is that the wharf is at water level. In summer, there are some open-air terraces where you could drink beer and eat "bitterballens" while admiring the surroundings. The area is filled with restaurants, cafes, design shops and mansions. My suggestion is to walk along the canal and enjoy the view.
A visit to Utrecht would not be complete without visiting the Dom tower and Utrecht's Cathedral. A curiosity is that both buildings were part of the same structure in the past. Unfortunately, a storm destroyed a part of the church and the locals never rebuilt the part lost so both structures remained separated.
Utrecht is wonderful during summer; there are many green areas where you could enjoy a warm afternoon. I particularly enjoyed the Wilhelmina Park and the botanical garden at the University Museum. The latter venue has a nice cafe. Speaking about coffee, Utrecht has many places to grab a delicious cup of coffee. My favorite places are De Rechtbank (on a sunny day) and Cafe Olivier, although this last place is much more suited for drinking beer.
Utrecht's main cultural attraction is the Rietveld Schroeder House. This home was designed by the architect Gerriet Rietveld who was part of the artistic movement De Stijl. Rietveld designed this home for a widow named Truus Schroeder. Rietveld and Schroeder collaborated in the design of the home and furniture and eventually became lovers. This house is now a UNESCO world heritage site because it is a milestone in modern architecture. Visits to the Rietveld Schroeder house are limited to twelve people maximum and there are only three organized visits per day. Booking is obligatory. The ticket also includes the entrance to the Central Museum. This museum has an eclectic art collection with a few highlights. My recommendation is to visit the Rietveld Schroeder house and devote one hour to the Central Museum, focusing on the Rietveld furniture collection. There is also the Dick Bruna huis, a museum devoted to the creations of the illustrator Dick Bruna (Miffy). I have never been to this museum but if you have kids, it seems like a good place to visit.
Finally, if you visit the Netherlands, you should buy some cheese. The best place to buy good Dutch cheese is Kaserij Stalenhoef. My suggestion is to ask for a mature cheese and combine it with membrillo (quince) which you could also buy there. I can guarantee that you will regret not having bought more.
