The building is confusing and not very modern
Good University.
History object. Go on Wikipedia and read about it
Not sure why Google says its a tourist attraction. It is in fact a university (university of Amsterdam), but it does contain a little book market. Besides, it makes up a fine piece of architecture to look at. Moreover, if you enjoy a cup of coffee in a pretty relaxed university building, or if you need to get some work done, then this is not a bad spot at all.
Had a nice tour explaining the role of this place in the birth of capitalism!