ESTEC (European Space Research and Technology Centre) in Noordwijk, Netherlands (close to Leiden, not far from Amsterdam), and luckily there was an hour or so to kill before heading to Amsterdam to catch a flight to Gothenburg, Sweden.
I say luckily, because ESTEC is also the site of Space Expo, a space museum that is also ESA's visitor center (the main Space Explo web site is in Dutch and has multiple pages and pictures - there's also an English site, but it's got very little content). This museum isn't as large as Cité de l’Espace (Space City), which I visited last summer in Toulouse, France, but it's pretty impressive nonetheless. In addition to the expected exhibits on the solar system, stars, space history, etc., there are a number of life-size satellite mock-ups suspended from the ceiling. There are also a number of interactive exhibits where you can launch simulated rockets and the like.
The ISS was represented by a cool model hanging from the ceiling (shown above with overexposed floodlights simulating a double-star solar system). But more impressive were the full size walk-through mock-ups of the Russian Zvezda and the European Columbus ISS modules (I realized again that the ISS is really, really big). There was also a life size Apollo Lunar Module mock-up on a simulated lunar surface with space-suited astronaut manikins for scale and (lack of?) atmosphere.
They have a nice collection of real space memorabilia including an Apollo moon rock, an airlock used on a shuttle Spacelab mission, and a section of the Hubble Space Telescope's first generation solar panels (returned on one of the servicing missions). There are some great large-scale models of Ariane launch vehicles (and full-size cutaway models of some Ariane rocket engines). I have a few additional Space Expo pictures on my Flickr site.
it appears that this book was also published in English, French, and German). The picture at left is the last page of the comic section of the book (there's a final section with photos of real ESA astronauts and more detailed text, all of which I cannot read).