1) The sights of Utrecht are gathered in one place, so that it’s possible to see them in one day. You should start with Dom Square, located in the heart of the city. In this classic tourist spot they serve very good coffee and fresh bakery almost on every corner.
2) Also, here is the Dome Cathedral. It is one of the oldest buildings in the country, perfectly preserved till nowadays.
3) Next to it, there is the highest tower in the Netherlands (112 meters), Dom Tower of Utrecht. And if you can go on top of it, you will see an excellent panorama of the surroundings. Its open hours are from 10.30 a.m. to 16:30 p.m.
4) Or take one-hour tour around the underground house, Dom Under, where you can testify 2,000 years of Dutch history, being kept under the ground of a few centuries-old square.
Entry fee is € 11 for adults and € 8.50 for children and students.
5) And then, you should definitely look into Utrecht Railway Museum at Maliebaanstation 16.
The city of Utrecht is the main railway junction of the country. Therefore, the existence of such kind of a museum is natural.
It is open from 10 a.m. to 5 p.m., and you should plan to spend at least few hours here. The museum is located almost in the city center, inside the building of the old Railway Station. A ticket for adults costs €16.
6)The University of Utrecht deserves special note.
First of all, it is one of the oldest universities in the Netherlands, and second, you will be surprised seeing such a beauty, hidden behind the walls of the University, if you take a walk in its courtyard.
7) Like many other cities in the Netherlands, Utrecht has its famous canals. Every day, there are tourist tours with the audio guide provided. One ticket is € 10. The duration of the trip is, on average, one hour. You will be shown ancient bridges and houses and pass through the most interesting waterways of the city.
8) Take a walk along the embankment that has shops, where, apart from souvenirs, you have to buy some chocolate. Belgian chocolate has gained not in vain its fame of one of the best in the world!
9) You can have a snack in the "Dogma Hotdogbar". This is very private and cozy place with hot dogs for every taste. The portions are big and filling. Or you can pop in the "Frietwinkel" selling delicious fried potatoes with a big choice of sauces. Grab it with you and go for a walk around the city — that's what it is great to do!
10) And in case you are looking for a cozy place with beautiful view, I can recommend the outdoor terrace of the cafe Heen En Weer on Donkeregaard 13. They have a good selection of beer, wine and snacks.
11) And in the end of the day, you can again walk around the Old Town. It becomes extremely attractive in the evening.
12) By the way, from Utrecht, you can have a one-day trip to the Castle de Haar (My notes about it are here.)
One day is enough to see Utrecht, but I would recommend staying here for a bit longer.
You can find much cheaper accommodation here compared to Amsterdam, and the level of comfort and coziness would be much higher. Especially, that it is just 27 minutes from Amsterdam.
