The Euromast takes you up to a hight of 185 meters. The view from there is absolutly amazing. I enjoyed my visits very much. I say visits because I went there twice, just a few days apart. The first time I visited the tower during the day. The second time we went there to have dinner in the restaurant on the Euromast (they were fully booked when we visited for the first time). The view is also very nice at night. If you can time it accordingly, come in the evening before it gets dark so you get to enjoy the view by day and by night.
Have a look at the webpage of the Euromast before you come. They offer a few combination tickets for musuems and so on. Also, if you want to eat in the restaurant (which I can very much recommend) don't forget to book in advance. Whoever is brave enough can also rope down from the tower.
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