One of the museums in Lisbon which I’d read a lot about is the Calouste Gulbenkian museum. Gulbenkian was a British oil magnate of Armenian origin who died in the middle of the last century. During his lifetime he kept his enormous art collection in his house in Paris. Although he donated many pieces to the British Museum and the British National Gallery, a significant part of it belongs to the museum in Lisbon.
The museum is housed in a stunning building which blends superbly with the surrounding gardens. The details of the design of the complex are described well in Wikipedia. What is difficult to convey is the aesthetics of the building. When you walk through the park and arrive at the entrance to the museum, it seems completely natural to skirt a duck which has settled near the door.
One circuit of the museum takes you past Islamic art as well as antiquity from Mesopotamia, Egypt, Greece, Persia and Rome. The Egyptian section is small but has a few stunning pieces. The Greek collection is remarkable: see the three examples above. The Islamic arts section gives possibly the best overview of this period among all the museums I’ve seen.
The second circuit contains European art. After you see a Franz Hals, a wonderful van Dyck, a couple of Rubens and a Rembrandt in close proximity, you can wander in a daze through the rest of the museum. I woke up only when I reached the gallery of French furniture, mainly gilded Louis XIV and XV. I remembered my camera only when I saw the plates above. The collection ends with Art Nouveau and Deco. The Family and I left the museum talking about this alternate modernism which now only appears in a certain kind of science fiction movie.